My folks had a Rotel RX400 when i was growing up playing records and taping hockey games off the radio, to time shift them for my dad when he was traveling.. (1972 Blues! Dan Kelly & Gus Kyle, and no I have not found any air checks dang it). It was a great receiver, and my college buddy wound up powering a set of large three-way speakers with it and was MUCH louder than I ever had experienced at home, lol! Since then I've always thought about getting back to Rotel, especially since their 1980's gear looked very slick and sounded just fine.
One of the main things I'd consider regarding *any* speaker system is whether you want a ported or tuned system that might emphasize the bass, or if you'd be content with a sealed box?
With vintage speakers, many of the tweeters are "horn loaded" rather than "front loaded" which contributes a particular tonality, along with some additional electroacoustic efficiency, compared to other designs like sealed/front loaded. Do you think shotgun mic recordings sound like they were made through a tube? Would you play otherwise "flat" recordings back through a megaphone for a tweeter? To me, that's what horn loaded speakers sound like, but there are reasons to choose them. Soffit mounting where the bass is naturally emphasized is an example. The extra efficiency of, say, a Klipsch horn-loaded speaker set might be just dynamite. I have heard such a system, and I will say the horn based speakers sound much better when they are further away from my ears.
I usually prefer sealed/front loaded lows and highs, but if BlueSky71's point about Rotel's brightness is true, a front loaded tweeter with a ported bass reflex design (for instance) might be great in order to get some more bass out of the boxes.
B&W has certainly made that kind of thing, so that would be a cool place to start auditioning, if that is possible.
Here's a ported bass two-way B&W, that might be keen in a small listening space, the DM110: (ebay image will eventually break)
Another matter is whether you want to pair with a subwoofer. On a vintage system I would think not, but that would affect overall bass levels a lot.
This is fun, shopping around with other people's money, LOL!