Here's a link to a scan from a page in a reference book (large image file!). According to the book, only 137 were built, the last being completed in 1965. The model in Damon's link is based on the one preserved example, which dates from 1961. Apparently, it's at the Black Country Museum, Derby; there's a picture of it at http://mudlark.fotopic.net/p15610565.html
Don't tell me you're a bus enthusiast as well, Doug?
Yeo, they still have one floating around Torbay. In 'Wallace Arnold' Livery
The Wallace Arnold one isn't a Guy Wulfrunian, it's a Volvo Ailsa. Both are quite similar, in that they have a front enterance alongside the driver, but also have a front engine. The main difference was that the Ailsa was a sucess, the Wulfrunian wasn't. Unlike the Ailsa, which other than it's unusual engine position, was fairly conventional for its time, the Wulfrunian had loads of advanced features such as air suspension, all round disk brakes, all of which cause problems, aswell as having a large engine unsuited to the front engine, front enterance layout, unlike the Ailsa which had a much more compact engine. They also suffered more conventional problems relating to the cooling system, and chassis. One other big difference was that the Wulfrunian was built in the late 50s, at a time when rear engined double deckers were new, and front engined halfcabs were still being built in large numbers, and was designed to grab the market who were still unsure about the new rear engined buses. The Ailsa on the other hand was built in the early 70s, with production running into the 80s, at a time when second generation rear engined double deckers were in prouction, and many of the revolutionary features of the Wulfrunian were standard, and many were in service until a few years ago, and quite a number still are.
I think there are still Ailsas in use with First Glasgow, I know Holloways in Scunthrope have at least one. One is preserved in the Tinsley Tram Sheds museum at Sheffield, they used to be the SYPTE standard vehicle but they were withdrawn long ago.