if the bus could be both, this is how it should look being based on a Daimler Fleetline:
The Manchester 31ft Daimler Fleetline
THE PARK ROYAL-ROE SALES DIVISION, which handles the products of Park Royal Vehicles Ltd. and Charles H. Roe Ltd., has plumped for an all-double-decker display at the Commercial Motor Show which opens at Earls Court, London, on September 20.
A total of seven vehicles, all two-door buses for one-man-working on rear-engined chassis, will be on display, either on various stands in the exhibition building itself or in the demonstration park. On the adjoining Park Royal and Roe stands there are to be four vehicles-a 33ft Leyland Atlantean for Sheffield Transport Department, a 31ft Daimler Fleetline for Manchester City Transport, a 33ft Daimler Fleetline for Leeds City Transport and a 30ft Daimler Fleetline for Birmingham City Transport.
A second identical Leeds Daimler will be on the Daimler stand, while on the Leyland stand there is to be a 33ft Atlantean for Plymouth City Transport. The seventh vehicle is to be a 33ft Atlantean for the Leyland demonstration fleet.
Although it is fair to point out that all the vehicles have been on order since long before the Ministry of Transport's standardization scheme was published, wide variety of thinking is evident, and four quite distinct designs, with few parts in common, have been used.
The Sheffield, Plymouth and demonstration vehicles are to the new Park Royal standard design, which incorporates what may be described as "medium-large" side windows, together with a vee-shaped treatment of the driver's windscreen and upper-deck front windows using flat glass. The glass-fibre domes are of the type giving a smooth finish on both outer and inner faces.
This design broadly conforms to the Ministry of Transport standard for a 33ft double-decker and it is hoped that it will not require more than detail modification as the standard is developed in the coming year or two. The floor is almost flat, with a height of 2ft 4in from ground level over most of its length but rising to just over 2ft 6in over the rear axle.
The Manchester vehicle will, of course, be to that operator's own recently introduced style, with generally rectangular lines, long window bays and an ultra-deep curved glass driver's windscreen. Much of the design is broadly in accordance with the Ministry specification, but the staircase faces the wrong way and the overall length lies between the 9.5 and 10 metre standards. It is anticipated that later 10-metre vehicles for Manchester will have forward-ascending stairs.
text and drawing taken from this website:
http://www.brindale.co.uk/ach/prv_site/publicity/bus_and_coach_sep-68_new.htm