Von Schweikert UniField One

This isn't a direct response to your question since I haven't heard the Uni Ones, but I will say that in the right hands, a coaxial design can give superb results. My Kef Reference 3s (why did I ever sell those?) had coaxials and the blend of highs and mids was just remarkable. Whether they were a match for those Jensens in your Impala--well, that's another question entirely. ;)

Love my floorstanding Von Schweikert VR-4 Gen IIs. But from my experience with the KEF LS50 (well deserving of all the praise thrown at it), I can also say that a coax driver can sound just fabulous. FWIW.

I have had a pair of Unifield Ones for a few years. They sound outstanding. I've driven them with both SS and Tubes.

I don't have anywhere to put them right now so they are in a box unfortunately. I should sell them but I don't want to be filled with regret like Stewie!