[Milsurplus] Headset - ?'s

[John Hutchins]

I purchased a Head set of EPAY for ~$20.00.  The stitching looked good 
and intact.  I received the Item the stitching  looked like the 
pictures! Wow.  Then I flexed the head band out a bit, oops needed new 
stitches no problem, leather dry'ish not brittle quickly got
mink oil on all the leather parts.  Wiping the rubber parts with Gummi 
Pflege  rubber restorer.  Wiped the cloth cord on the HB-7 down with 
bees wax to preserve cloth insulated wire.

Checking on the web it looks like a WWII+Korea+Vietnam hodge podge set up.
Headband HB-7  (WWII)
Speaker elements, ANB-H-1A, encased in rubber with shammy leather ear 
cups.  (Korea?)
Microphone M6-A/UR, on boom MT521/AU permanently affixed to left 
headphone. (Korea Vietnam?)
Cord CD 318-AM with SW-141V PTT switch, PL-68, JK48 (WWII)
Cord CD -?? with JK26 and PL55 (WWII)

CheckN out the electric components, with an audio generator and VOM.
The Speaker elements, ANB-H-1A, responded well to stimulus from audio 
the generator.
Switch works correctly.
Cords check out.
Next Microphone M6-A/UR, shows resistance.

Quick way to check if the microphone works, with out hooking up an amp?
    Is the microphone dynamic or carbon could not find a reference using 
a quick google search?

Is there a better rubber restorer solution than Gummi Pflege?

Thanks
Hutch