I had a 72 with rusty wheels, but they were well made rims and were still viable. Over in Europe, those bikes were known as shoppers and got daily use for years, and they held up. Yours looks like someone painted the rim silver instead of cleaning up the chrome years ago. I'll bet the rust isn't that deep, but as noted above, you'll have to inspect the inside also to be sure. Then maybe just clean them up, wire brush, and repaint silver. If you decide to go with new rims, I'll agree, alloys will be best, but the cost to have them laced up might be a lot.