Finding that Connector.... convert to XLR?

Sometimes it can be a harder quest to find an audio connector from bygone days and pre the standardisation of the marvellous  XLR connector.
Some do appear from time to time , but again they can fetch a financial premium because of the hens teeth factor. With attempts to be sympathetic to the original microphone adaptations can be made to make interconnection simplified.

Some machining can be done from existing options to fit [mod an existing plug] or originals can be manufactured from brass aluminum or even 3d printed

Grampian 3pin made from scratch 3d printed ABS plastic with brass pins 

 

Neutrik plug re-machined to fit within the Reslo RB ribbon mic