Hi Simon,
I have never seen one of these logos. I am a newbie at all this however I do restore vintage stereo speakers as a hobby to keep my mind off of things. One thing that might suit you is if you can find a picture of the logo you are seeking a trophy shop might be able to fabricate one for you. I know regarding stereo speakers like “Epi”, “Epicure”, “KLH” and such can be reproduced to near exact specifications.
I will upload examples from my Epi 1000 speakers. I took in an image of the Epicure logo and asked them to fabricate an exact match only with a bit of mods because the speakers were restored better than new…. The former owner of the company back in the ’60s/’70s followed the resto and gave me tips and such.
Anyway, I do hope this helps you in some sort of way..
Best
Jer