Classic 46mm Athena kit for Peugeot 103, 105, SPX, RCX, Fox, and Honda Wallaroo. Large side transfers and L shaped top ports. Piston is single ring with a window. Aluminum with nikasil plating. Based on the discontinued Eurocilindro kit. I see a lot of case-matching in your future.
Comes with cylinder, piston, ring, pin/clips, and gasket set.