... it just happened that the MkIII and the EPA100 MkII were introduced contemporaneously, or nearly so.
EPA-100mkII tonearm and SP-10mk3 turntable were introduced in 1982 together. This limited edition tonearm was made for SL1000mk3 combo in 1982. http://audio-heritage.jp/TECHNICS/player/sl-1000mk3.html
Any other Technics high-end tonearms, including EPA-100 and all variations of the EPA-500 and EPA-250, were introduced in 1976-1979.
So the world premiere of the best tonearm Technics ever made was in 1982 along with their best turntable ever made (SP-10mk3).
http://audio-heritage.jp/TECHNICS/etc/sp-10mk3.html
The price for EPA-100 in 1976 was 60 000 Yen (same for EPA-250)
http://audio-heritage.jp/TECHNICS/etc/epa-100.html
Price for EPA-500 in 1979 was nearly the same, 65000 Yen.
But the price for EPA-100 mkII in 1982 was 130 000 Yen
http://audio-heritage.jp/TECHNICS/etc/epa-100mk2.html
That was an extremely expensive tonearm!
That's why i think there must be serious advantages of the limited edition EPA-100mk2 over the previous EPA-100 and EPA-250/500.
In 1983 Technics introduced their P100c mk4 MM cartridge
http://audio-heritage.jp/TECHNICS/etc/epc-p100cmk4.html
... and this amazing SL1000mk3D combo:
http://audio-heritage.jp/TECHNICS/player/sl-1000mk3d.html
In color it looks much better:
https://i.pinimg.com/564x/d0/b9/6d/d0b96ded2f1afd332b8f03dbbf37d2d6.jpg