I picked this up the other day really cheap with a view to 'do it up' a bit for display purposes.
The guy I bought it from said it was his for childhood in the 60's so I thought is was something his dad may of 'knocked up' if so why do i recognise it as something I have seen before, two other people have said the same since.
The VW is 1:32 scale for size purposes, I must admit I like it as it is, with the stickers added, even got a tin plate car lift
I'm almost positive it's not homemade. Lots of wooden garages/gasstations/workshops/fire stations were made in the 60s, many of them from well-known diecast makers to complement their cars. Others came from toy brands not normally associated with cars.
I had a garage/gasstation from Hanse (I think) and I know Tekno (to name just one) also made some.
You've probably searched for a name stamp somewhere, but just because you can't find one, doesn't mean it's homemade - some makes stamped their names on, but others just used stickers, easy to remove or wear off.
Finding out what it is won't be easy (unless somebody here knows it, of course) One clue could come from the various stickers: I can see a lot of international brand names, but possibly also a few that I don't recognize - find out the nationality of these, and you could have the country of origin for your garage. You'd still have a long way to go from there, but at least you'd have a clue where to look.