DAMN Riders - No rules, Just ride!

Having the luxury of being able to do this in the garage rather than on the trail is a huge Advantage. You can use the leftover chain to try to recover a usable link. When recovering the link that you will use as a master link, avoid grinding down the peened end to remove the link. Pinch it with vice grips , hammer it from all the way around with a punch, or even grind away the links around the pins of the master link you're trying to recover. Then you could either roll the pins back to original diameter, or squeeze them with a Vice so they will fit into the new chain , but I would try to retain all the original material so it leaves me enough to mushroom back into into a suitable peen, and hopefully reduce the risk of deforming the pin with my Hammer blow.

Thank you. You all have confirmed my thought process on this. Sacrifice a side plate to save the pins, sacrifice the pins to save a side plate, combine the good parts and re-peen.
I've actually thought that since I can get likely get one entire pin out intact, I could just press that into a chain where I left two outer plates hanging on one end and the inner link hanging on the other. Not a full master link, just press in one pin. That would disturb the chain the least.
I'll buy some chain and give this a try.