They used those engines on a zillion things, air compressors etc. I am pretty sure he will be able to get them through NAPA especially if it is one that has a machine shop. Surely they have been through it before. What worries me is they were stuck bad enough to bend.
Hopefully they can get his needed parts. I'm thinking backwards in the fact that push rods are bent, and hoping the valves not opening created that instead of them open and the pistons hitting the valve heads. Still could be issues in that area but I would eliminate the obvious first.