I have a 1952 Jacobsen Model 18 rotary disc mower that I want to restore. Does anyone know of a source for a new piston and rings for this 2-cycle engine? It has a 2" bore and top of piston is raised on inlet side. Original part number for piston with rings is A-4559. May have to get some pistons fabricated by one of the piston manufacturers if nobody has anything available. I realize this is a needle in a haystack proposition, but thought I would ask.