|Melodium 78A cardioid dynamic microphone|
Here is a scan of an English language Melodium product catalog for their line of microphones, which (probably) dates from the 1970s. It includes the RM6 ribbon microphone, 76A & 78A cardioid dynamics, and 77A, 79A & 88 omnidirectional mics, along with a range of accessories.
French language data sheet for the RM6.
Melodium C163T Data sheet
Many thanks to Santiago Ramos for sharing these.