The engine is an A14 out of a '79 210. This engine had the late model round port intake, and the 8.5:1 low compression (deep dish) pistons - from what I can surmise these were part number 12010-H7284. These were unique as they had a very slim top ring that is 1.2mm rather than 2mm like all the others.
The 9:1 compression pistons are the very common stock "shallow dish" pistons. Part number 12010-H7284 - I know the correct Sealed Power number for these is 12147P as I have 3 in their boxes.
Cylinder head has already been replaced with oval port and twin SU carb setup.
So - I have 2 sets of three pistons that can't be mismatched or swapped. If someone has any single standard size (76mm) A-14 piston - I would be good to go! Will pay whatever - just need to get this thing back together!
Thanks,