These unidentified, forged pistons came from a Matchless dealer. They may be for a single or a twin cylinder.  The numbers on top are " 80.4-6614. No other identifing marks. Looks like they take standard (British) thickness rings. They seem to be in normal new condition. I do not have the original box. They have been on my shelf since the early seventies. Hope they are good for somebody. Pins included but no rings or circlips. Pins have a streight internal bore. I just found 2 new piston rings in the bottom of the box. 1 comp the other is a one piece oil ring.  Save money with combined shipping.

Someone suggested these could be Moto Guzzi as they have 22mm wrist pins. Guzzi pistons are different domes and the motor is transverse.

Someone suggested that these may be for a Yamaha XS/TS 650, 1970-1973. That engine had a stock bore of 75mm. That would work out to about a 735cc big bore due to its short (73mm) stroke. The standard size for a Yamaha XS 650 big bore is 80mm.