Matchless AJS G80cs barrel cylinder & Piston Vintage AHRMA 18CS AMC Rickman For Sale

Matchless AJS G80cs barrel cylinder & Piston Vintage AHRMA 18CS AMC Rickman.

This barrel/piston came with some Matchless G80cs parts. It is a bit of a mystery, may be a big bore kit or could this be for a typhoon? My cheap calipers measure the piston at 87.5 mm. One small broken fin as pictured. Please Study the pictures closely and ask questions before purchasing, I do not accept returns. Thanks for looking!