I had a couple of junker Magnum 40's, bought really cheap. One had an ABC liner, the other liner was the same shiny color inside and out, so I presume it was ABN. I parted them out and put together one engine. I used the piston from one in the liner from the other (sorry, I'd have to go out to the shop and look at the discard to tell you which liner). I've given the engine three short break-in runs on the bench and got three one-flip starts. It may turn out to be a good engine.

Jim