you guys are too good.
I'm now thinking the tank is either 250F or G, I've looked at the VMX mag with the article on them and I can't tell the difference? The reason I was thinking 125 is that I thought the 250 tanks were much larger.
The pipe is indeed either rm125n or t. Funnily enough I've got a PE175 and a pipe for an Rm125N in the shed, and I didn't even think to look. The guy had passed the whole lot off as yz125f stuff, so I figured he'd just got the year wrong, not the brand as well
The small wheel is a JR50, 1994 model, well spotted. The larger is YZ Yamaha, kudos to you Doc
I'm also positive the milk crate is stolen
And yes the pipe is available for sale, I have three pipes for one bike so......