Interesting, I thought it was from London and 1935 (prototype).
Actually you're right about the date; I had it as 1937 but that is incorrect.
So as per the picture you have posted it's a prototype Leyland TTL Low-loading trolley-bus.
But it had nothing at all to do with London! I know it appears on a London Bus site but that's just someone today illustrating that this 77 year-old bus could serve today as a suitable replacement for the much-loved Routemaster, with its modern front door AND an open rear platform (just like the brand-new "Boris bus"!), plus the attraction of zero-emissions. I know its picture also appears on a London Bus Pictures website, but that picture is of the bus doing a demonstration run in Bolton. There is no evidence at all of the bus ever going to London or of London Transport ever being interested in it. Sadly this bus, which was quite advanced for a 1935 British design, never entered production.
Anyway, you've identified what it is so that's another point for you!