I have had a reply!
It seems he is preparing a new batch of the GSR 800 kits, so the potential customers that I referred to Des could end up happy. He confirmed he had received their e-mail separately and had replied to them individually.
I'm not sure there were a limited number of prototypes. If Irish locomotive history tells us anything, it is that there were a great many locomotive classes, albeit many (most?) only containing single figures.
I wondering how the spring carrier behind the iron is supposed to run straight if there's no allowance in the iron itself for the bearing to run up and down.... Bill generally put in an oval hole so that the bearing could be guided. It looks like he forgot to design it in here.
Over the weekend, I've had two people asking me about Des Sullivan @Weshty. Both want to buy his 800 class kits, but it seems he's not answering website e-mails.
I hope nothing's happened to him.
I recently offered two 7mm A5 full point kits on eBay at half the current retail price each. They contained everything including pre-formed blades and common crossings, plus gauges, and were very quickly snapped up!