[ARC5] Microphone XFMR?

[Brad Hernlem]

Anyone recognize this transformer?:

http://home.att.net/~b.hernlem/OZRlike.html

It was suggested that this might be WWII era microphone input transformer. 
Respondant thought ARC-5, possibly, although I doubted it. However, if it is 
mil, maybe someone here recognizes it.

"M" to "A" is 7 ohms DC res. "G" to "G" is 1.7 kohm and "C" is midway. Maybe
a carbon mic to P-P grids input transformer but what do those terminal
designations mean? Guess and suggestions have included "mic" for "M", "grid"
for "G" (those are the easy guesses) and "A" and "C" bias rails for the
respective terminals. "C" could also mean "center-tap" or "common" but it
does not go to case.

Dimensions are like UTC's "ouncer" transformers but this one doesn't match
any of their descriptions, is different in that it has a brass plate on end
opposite terminals and has the funky designation scheme. Side of case
appears to be printed with a "10" and there may have been other letters or
characters that have rubbed off (not shown in photos).

Brad
KG6IOE