I think that depends on what you're trying to achieve!

Aluminum "28 inch" rims, the size later known as 700x, are pretty rare. So I'd think these are quite a find.

But my guess is they are not hooked (this you can check) and a pretty soft material (harder to check). Once unbuilt, you will probably find that they aren't particularly round. I could be wrong! Let's hope I am.

I don't expect that. I'm sure you can build them up to a nice, vintage and useable set of wheels, but no way I'd use them on a commuter. On the right vintage bike, maybe more of a showpiece than a rider, they'd be lovely.