I doubt it will be easy to get your hands on a new piston for an old Pope 2 stroke and probably cost a lot more than a good second hand engine.
I've bought a few old Pope 2 stroke mowers and the sellers are lucky to get $30. for a complete mower as there is very little interest in these old mowers.
People can advertise them as much as they like but unless they are like new ,these mowers don't sell for much.
If you look on eBay or start ringing every mower shop you can find, then you may get lucky and find one but sometimes you just have to get one made from a piston manufacturer like JP Pistons if you don't care about the cost.
