Philips, Luxman, Sony, Yamaha, Sumiko etc. all had yokeless cartridges in production well before Transfiguration was even founded.
Philips' GP922 and GP922Z were launched in the 1978~79 timeframe,
Yamaha's MC-1X (also from the late 1970's) used printed-circuit coils and no yokes (AFAIR),
Sony got involved with the early-to-mid-80's XL-MC** series
Luxman's LMC-1 and LMC-2 designs were from 1980~1981
Ortofon's MC-200 was also from the early 1980's
Sumko's Talisman cartridges were from the mid-late 1980's.
These were all yokeless cartridges that were in production before Transfiguration was even founded.
FWIW, I believe that the Transfiguration designs were a spin-out from Supex - when we (Lyra) were still working together with Supex (early-to-mid 1980's). I knew that Asakura (Supex owner) was working on a yokeless cartridge design.
At the time, Yoshioka was working for a large trading company called Ohsawa Shokai. In addition to his normal import and export work, Yoshioka was an audiophile, and was fairly close to Asakura. Yoshioka had Supex OEM a line of MC cartridges which were branded as Ohsawa and exported.
In a few years, Asakura's health began failing and he retired to the countryside, but I heard that the yokeless MC project was kept alive and Yoshioka subsequently took over the business.
hth, jonathan carr