I was looking for any possible info on the internets about the 31 Guinness Tanks built by BR 1951-1955 and I've stumbled across posts made by Mike Smith, I think he's the one with the long and thorough page about beer road rail tanks on his website.
I am not sure how to contact in private message on this website, but I'm 3D modelling the Guinness Road rail tanks, there should be a picture attached here. So far my only source is the much info on my similar thread over on RMWeb, and Mike's site.
One of my questions, if Mike is still around: was the original 1951 lot of 18 wagons built with the 13' wheelbase with 6'6" spaced wheels? It looks like the later diagram of 13 wagons was the 16'WB variant with 8' spaced wheels.
I believe I read on the Road rail tank (Guinness) here that there were other pictures of the Guinness road tanks. In terms of online, this is the only picture I've come across