I had been avoiding bringing this up as I thought my memories may have been fading over the years and that I had my timelines mixed up, but with some spare time over Easter I dug through some old files and found the actual receipt for my optional Yamaha Alloy swingarm that I bought early in 77 for my 125 D that I was racing.
In essence this arm is the same as the āEā arm that came out the following year.
This should be proof enough for anyone to run an E arm in their D now.
Suzukites will have to keep searching some more for their proof.