I have (12) USED 76mm bore "short" A-series pistons for sale without rings or pins. These are wedge dome, forged pistons by JE. They use commonly available ring sets. [They use 19mm pins.] USED price $25 usd each piston. [NO pins.]

Compression height is 0.972 inch.
Stock A12/13/14 compression height is 1.279 inch, so these are 7.8mm shorter than stock A12/13/14.
Stock A15 is 1.180 inch, so these are 5.3mm shorter than stock A15.

I can email pictures. These can be used in A12, A13, A14 or A15 with custom length connecting rods.

Thanks, Peter
Email: PeterZekert (at) Juno (dot) com