After I split the cases I checked the crankshaft over and couldn't find anything wrong with it. I thought about saving some money and just reinstalling it, but the odometer indicates the bike has over 60,000 miles on it, and I did find the factory seal on the engine, which led me to believe it would be best to have it looked at by someone with more experience. So I boxed it up and sent it off to Syd's Cycles, in Florida.
Six weeks later (I had told them I was in no hurry) I got a call from Syd's son, Malcome. He told me they had checked the crank over and found nothing wrong with it. They magnafluxed everything and then put it back together with the old parts, simply reversing the thrust washers. I was pleasantly surprised to hear this, and Malcome was surprised to hear the bike has over 60k miles on it. "It looked more like 6 thousand" he told me. When I asked how long these things usually last, he told me he knows of one with about 80,000 miles on it now. I guess the lesson here is that the 750s aren't so hard on cranks. I doubt this one has been treated all that well, judging by the rest of the bike. Or, perhaps the original owner was meticulous, and the next owner was a hack, but fortunately something else went wrong to sideline the bike before he could screw the engine up much? Who knows...