RoG's idea of making a kit of a typical London bus was not new.
About thirty years earlier Heller introduced a kit of a typical Paris bus. This kit has been re-released some time ago and should be still available today.
The 1:1 vehicle of Heller's kit was a ubiquitous part of the Paris cityscape for decades. It was a Renault design called TN that was introduced in the early thirties. TN4 had a 4-cylinder engine, TN6 a more powerful 6-caylinder for the hilly areas of Paris. Bodies with an open rear platform were used in the city areas, entirely closed bodies were used in the suburbs.
TN6 were in service until 1969. The only design modification in almost 40 years was made directly after WW2 when the half-open driver's compartment was closed for better wheather protection. The Heller kit shows such a modified vehicle.
I was not able to clarify when Heller released the kit exactly, probably it was 1980. I built my model when the kit was rather new, so after such a long time I cannot say much about the kit. I remember, however, that there were some fit problems of the bonnet parts. Apart from that I am quite sure that there were no major issues because I never had major issues with any Heller kit I built.