I also tried a new repop seat from the UK on a 158 Sherpa, wasn’t even close,,

Fill with white vinegar for a few weeks. Wash out with Inox to stop flash rust.

@ David - What model engine are you looking for to put in your SM frame?

This is a pic of frame SM49

Interesting information on the frames. I have an SM frame, number SM49. It has a M49 engine and a slimline tank. The bike is in the USA still.

Has anyone used one of the Forseti brand pistons in their TY?

I have one from shedworks. Good value for money

A few bully basket cases and a couple of pristine ones I have in the States I’ll bring back at some stage.

What lubricant are you putting the tyres in the rims with? Sometimes if it too slippery and you don’t clean it off nothing will stop the tyre spinning in rim.

I bought one from shedworks so you can email me any questions if you like.
Email - [email protected]