What vintage speaker might you use today

Right Jim, the transmission line loading of the woofers in the ESS "Trans" series speakers made for unusually deep and tight bass for the time. The dome tweeter in the lesser ESS' was okay, but those RTR ESL's in the Trans-Static were SOTA. Fulton used the RTR add-on tweeter assembly (which contained six of the tweeters) in his Model J loudspeaker in '74, another really good one.

I have a good num of vintage loudspeakers about and a few that are modernized. Mostly I use my Community Extended Leviathans with 4x 15in altec 515b- TAD 4001 midranges- Fostex t500amk2 tweeters. I also enjoy my RCA MI Shearer horns they have a real type of sound quality and even jaded industry professionals have fawned over them.

Jensen Imperials with the 15" Triaxial loudspeakers.

Tannoy Gold 15" with GRF Rectangular

Just can't seem to stop listening to my Quad ESL57 rebuilt by Wayne.

I have much more current speakers in my closet that just don't give me the pleasure of this vintage design.  They are just wonderful!

One of these days should probably sell the rest.