They are pretty rough guestimate, another look tells me pistons more like 25 mm and maybe 26.5 mm on bore

I'll measure mine tomorrow and get back to you. The seal is 26mm outside diameter so your bore would probably be less than that I would say.

Here's the measurements but for some reason the piston diameter kept coming out higher than the bore diameter haha. I couldn't get the verniers far enough into the bore. The piston is a nice snug fit with a small amount of movement.

Andrew it looks as though we both won't have any worries there, go fo it mate , especially with the v seal you'll be sweet. Looking forward to seeing your progress going forward.

Cheers. I'll have a crack at it in the next couple of days. Once that's done it's ready to ride so fingers crossed it'll work.