As already mentioned by others, there are no correct 700c clincher rims because they hadn't been introduced yet in 1973 (at least in N. America). When 700c first became available it was mostly as a convenience for racers who wanted to swap training clinchers with race day wheels (sew ups) without having to readjust the brakes. It was a small niche.

If you really want to be concours correct about it, the wheels have to be shod with either vintage Weinmann 27" rims, or tubulars.

Vintage clinchers sucked. Both the tires and the rims. Therefore, I'd suggest not being to OCD about it and using a modern rim with a polished finish instead. TB14, Sun M13II, etc. Nobody will be able to tell from 6 feet away.

Or put sew ups on it...