I just got a wheelset really for the hubs and I want to flip the rims. Both are 36 hole Fiamme and look the same at 3 feet but they don't match. One is stamped "Brevatto Longhi Fiamme Made in Italy" and has an eyeletted valve hole, clearly a 50s-60s rim. The other is stamped only "Fiamme Italy" with no eyelet, something from the 70s. Both have lost their decals.

So, do I put them up separate or as a pair?

Separate, but I would reference the other in each listing.