I measured all 5 pistons:
Original size is 82.485mm.

Piston 1.......82.44mm
Piston 2.......82.44mm
Piston 3.......82.45mm
Piston 4.......82.44mm
Piston 5.......82.44mm

Complete with piston pins and circlips, no piston rings!
Piston set needs to be cleaned, i allready cleaned one, the others you may clean yourself.

Price, 75euro.