Hi Wozzly
I seem to have P/Ss with round Din connectors. My C128 has a square power connector like the Amiga. I don't know if the signals are the same between the Amiga and the C128, I haven't used the C128 in years. I have no spare Amiga P/Ss, sorry.
It seems that another poster may be a one stop solution for you.
Good Luck!