Many thanks for the replies.  I have never seen actual photographs of the Mercedes or Auto Union before.  The Dinky versions look like very accurate reproductions of the real thing, both great looking vehicles!

I have noticed another apparently pre war Mercedes 23 racing car on eBay this week  with a clip in rather than riveted base plate:





 





The body casting and clip in baseplate design appear to be different to my yellow Mercedes below.  The blue one above seems to have 4 positioning points / baseplate cut outs as used on the later riveted version.  If this model is correct it looks as if there was an intermediate step between the early and riveted base versions? Or could this be a non rivet base plate adapted to fit a riveted body?

Hi, I always had the 'feeling' that a pre-war example was less heavy than a post-war one.

So now, regarding your query, I thought I should make an experiment and put a pre-war example on a balance and subsequently a post-war example. And this is the result:


Pre-war (1936-1938, without rivets): 68 grammes


Post-war (ca. 1950, with rivets): 78 grammes

All my other post-war examples do 78 or 79 grammes, so there is no significant deviation!

It must be due to the extra spigots inside + the rivets + the thicker axles that the post war model has a surplus of 10 grammes!

Kind regards, Jan

Jan, you conclusion makes sense to me on the weight difference as there were no post for rivets in the early pre war toys

Unfortunately I can't weigh the blue one as the picture comes from eBay.  I have however noticed another one with the same baseplate design sold on eBay.  This time it is the same colour as my own so would not doubt it is pre war. It does however look like there was some evoloution in design before the riveted version appeared:



Above 2nd version I have seen on eBay with 2 cast pillars either side before and after the wheels


Below my car which does not have these pillars:

I did not really answer your question and in fact I cannot. It is a curious transitional situation because this means that the base plate has not been changed once, but twice. First the old base plate adapted to accommodating the pillars aside, then a new moulded one with a new flat bottomed engine block, turned lettering, the model name added and the holes for the rivets. One might wonder if the spigots are inside already. You might try and weigh!


Another picture showing the original (yellow) and final situation.

Regards, Jan

Thanks Jan,


Unfortunately I don't own either of the 2nd type non riveted examples shown but if anyone does have one it would be interesting to know the weight.  As you say the rivet posts could actually be present.  I also wonder what is holding the base plate on as the previous crimping points are no longer present?


John

No spigots in the second variation. Note the small holes in the four boses, they may have been used to enlarge the boses after the base plate had been positioned or made with a punch with the same result. These holes do not exist on the following variation with spigots.

Thanks Jacques, this explains it; on both the pictures I found (blue and yellow) there are small holes in the 4 boses.  I guess that these boses were then a redundant feature once the spigot and rivet was introduced in the 3rd version.


Does this 2nd variation also apply to the Auto union and Speed of the Wind as well as the Mercedes?


I have a further question; I also have a blue post war Mercedes that was overpainted and I have restored to it's original colour scheme.  When I stripped off the overpaint I found that the metal base plate had a silver finish so left this unpainted.  Is this correct or would the base have always been painted on a post war 23c as in Jan's picture above?

Hi, in my opinion the silver 23c's had a silver finished base plate only, see the samples below:



Regards, Jan

The hole at the center of the base plate is a painting hole. The base plate was assembled to the body before painting, the wheels were added later. This is why the base plate is the same colour as the body what ever the colour, blue, yellow, red or silver. This does not apply to the Auto-Union with driver and may be the reason for deleting this figure.


The four boses could not be removed as this means adding metal to the die. Although this is technically possible by adding four inserts in the die, it is very costly and would have also required to modify the stamping tool for the base plate as well.

The early 39 series had silver base plates, they were not painted, I think that they were tin plated or some other electrolitic treatment. Later, the black base plates were pre enameled before been stamped and cut.

When you study casting variations, always think that adding metal to a model means removing metal from the die, this is pretty easy. Removing metal from a casting means adding metal to the die, this is either difficult or costly and I can not think of an example on Dinky castings. To makea variation, some time, one part of the die was replaced by a new one such as with the Triumph Herald to turn it into the Vitesse, the VW Kahrmann the front of which was wrong, the 3.4 Jaguar to make the Daimler.

It is obvious that at that time (1936 - 1938) Meccano was looking for the best and most cost effective way to make these toys and that several tests were done before establishing the construction with body + base plate + wheels and axles as for the 24, 25, 38, 39 etc… series.

janwerner wrote:
  


Hi Jan,
a great idea that I absolutely had to repeat.

And here are the results of the German jury.

My personel results of course, but very surprising.

All Mercedes-Benz • Dinky Toys 23C

1. Prewar without clip in points. 68 g






2. Prewar with clip in points. 72 g





3. Prewar with clip in points, racing number 10. 105 g !!!
(this is the car above watched on ebay, I spent some original herringbone tyres)




 

4. Postwar riveted, racing number 1. 76 g







5. Postwar riveted, racing number 1. 78 g






6. Postwar, French, metal wheels, riveted, racing number 1. 76 g






7. Postwar, French, rubber tyres, riveted, racing number 4. 72 g






The weight of the third car was very surprising. First I thought there must be something inside of the car. But there is nothing. The cast is the same like the cast of the yellow car. So my guess is: The car is made of lead. If the dry density (?) of the mazac is around 7,6 g/cm³ it could be really lead.


How could this be? Any Idea?

If you have two of them you just need some scales to weigh them both. That would tell you as the heavier one is probably Lead

How you can see I have two of them and I weighted them. The yellow car weights 72 g and the blue-green car with racing numer 10 weights 105 g. The density of lead is 11,342 g/cm³. The density of zinc is 7,14 g/cm³. But what I don't know is the density of the zinc alloy which was used at that time. If the density of this alloy is around 7,77 g/cm³ the material of the heavy car could be lead or a lead alloy.


But I never heard or read about a Mercedes 23c which was made of lead. Thats the point! It doesn't look like a fake. This is really exactly the same cast like the yellow car.

I have heard about lead Speed of the Wind and  Thunderbolt but not yet about the Mercedes. Why not after all.


One way to test your model is to check the melting temperature which is lower for lead 327° than for zamac 400°. lol.