IIRC it was usually supplied with a K-PO DM 520 type but bear in mind you need the dynamic not the electret version & you'll have to change the plug to a 5 pin DIN or XLR & wire it as page 20 of the technical manual- or copy the wiring from the duff one.
Seems expensive when you add the postage from Netherlands ?40ish
Do you have any spare ones Bob Smith?
Would you be willing to loan me one for the summer?
It's for a diving project in Spain where we will be camping beyond a very long sump for 3 days , currently without communication.