The OTL3s are almost impossible to come by. I’d be surprised if there were 1,000 pair surviving, most in Japan most likely. I can ask Jon to keep an eye out for a pair, but short of having him build a new pair from scratch, you may be waiting a long while.
I believe that Atma-Sphere makes a pair but I am not sure, and I think there is a company in Texas that introduced a model a few years back. I never heard either so I cannot vouch for them. I have heard a recording of Mikis Theodorakis’s “Canto General” that was recorded and mastered by Atma-Sphere: I found it to be a little disappointing from an engineering point of view, sadly so since artistically it competes well with the Farandouri performance.