I'd offer him a low ball price as they sit, and higher price if they check out as rebuildable. Tear them down and send them to a machine shop to be blasted and magged.
Give him $500 with the agreement that you will be back with $500 more if they check out. If they dont. agree that you will bring back for $500. He gets two checked out motors for free. You are honest. He knows it. He is honest. fair deal.
