They look like cheap vinyl-covered speakers. Marantz did make a few decent speakers, but these aren't them. I'm actually confused as to where these might have come from, since to my knowledge, Marantz never made a compact system*, and that is generally where you'd see speakers with RCA input jacks.
In fact, don't the grills look like they're two different colors? Maybe they're not Marantz at all, and someone slapped a Marantz grill on one.
If you're looking for something that's going to look nice, I'd try to find something with real wood veneer, at the minimum.
*I'm talking about a 1970s compact all-in-1 system, which weren't actually all that compact, compared with the more modern shelf system which is a lot smaller.
