In rebuilding a B-series engine (1950cc) I needed a new set of Omega Piston Rings (for 83.5mm Omega pistons, #3649). I ordered these from www.shengineering.co.uk. However it turns out the oil control rings are too big - I understand that they changed from 3mm to 4mm at some point and mine need the older 3mm ring. All the other rings in the set I bought are OK.
Contacting Omega hasn't helped.
Does anyone have any idea if there may be any places that stock the older rings?