I've used standard 5 pin DIN plugs before. Remove the casing, there is a little work required to the body...sandpaper.
They fit the Grace arms no probs. Rega they need a little work...building up with epoxy or black electrical tape on my first try.
The 270 degree 5 pin male will fit a Grace plug, but the pins just need to be made a little thiner...file or glass paper.
It is fiddly work, but you can do it for less than £1 if you try.
Anyway it helped me out just to try some of the arms I've got.
Maybe not perfect, but it works.