If you don't, do you have room for larger speakers or floorstanders? Don't get me wrong, I'm hoping you won't need to go that far - but whilst they weren't great recordings to my ears, they are listenable and do have 'groove'. I am wondering if what bass the recordings have does help to some degree.
The closest I can get to describing the vocals is still not very close, but some of them sound a little like they are being played on a Dansette portable record player in the soundstage. It must be a deliberate 'sound' though, as other recordings from that era can be very good and very natural indeed.