He hammered on the hubs to get them off the drums because they were seized together. If it were a regular shop, I'd definitely make them pay for it. But this is a guy working for himself, and he's always done good work for me at a reasonable price. I'm just going to chalk it up to old truck complications - sometimes parts get seized together and you end up replacing an adjacent part too. In other words, I'll give him a pass this time based on my past experience with him.
I guess I'm going to buy the new hubs. I can always return them if that turns out not to be the problem. I am pretty sure - as sure as I can be based on what I can find - that my '74 has the same hubs as the later years, AC Delco RW20-124 (OEM # 03977397). The drums are the same, and even though no part search engine shows a hub for the '74, I can tell the Delco part is the right one from at least the late 70s until 2000. One of the compatible models lists also shows the Cheyenne, which I think they stopped making in '75 or thereabouts. Does it sound like I'm making a reasonable assumption?
This is the only time I've had difficulty locating a part for my truck. Pain in the ass, and I don't like guesswork.