To Bdp24, I am not a hi-fi historian, but may become one if keep asking about the so called vintage stuff. You are right,I must be as old as you at 68.
I fondly remember hearing the ESS Translinear speaker and the Transtatic and was blow away to use an overworked 70's term. A small audio store in Redwood, California carried the line. I fell in love with the sound especially the deep tight bass. I did not have the dough (or room) for Transstatic, and should have gone the extra mile,and bought the Translinear, but settled for the ESS model 7 which was just below the other two, but still sounded outstanding.
One of the key components of the line was the use as you mentioned of the KEF B139 woofer/driver which produced the tight bass. I later found out the tweeters, at least in the ESS 7's were made by Philips; that may have been also true of the Translinears. In the model 7,the Philip drivers tended to sound bright, even in the days before CD's and digital glare.
It is good to know someone still has a pair of these amazing sounding speakers (at least for their time)