Ah yes I have the Railtruck built by a friend, did not appear in my Irish Stock thread so must do an update.Hi Jon
No, not got around to blogging the build yet.
Not sure if John actually still trades. I twisted his arm at Llanfair a couple of years ago when he was exhibiting one of his small crane layouts and we got talking about Deltang gear which he uses.
I think it must be 15mm - I've not checked the dimensions but I can only fit the smaller figures into the seats and cab.
I'm thinking of double ending the railcar to avoid turntables. The latest plan is to make an unpowered model of the Walker railtruck, but construct it so that I can slot it on to the power bogie when I fancy just running it as a truck. I've discovered that that is how it was used on the Clogher Valley. The body was detachable so they could use the power bogie as a spare when the railcar bogie was being repaired so it looks like I'm accidentally repeating history but for my own ends!