[Collins] SM-1 microphone

[Jim Isbell]

I have a Collins SM-1 that I was trying to sell or trade a while back 
because I had no way to test it and did not know how to open it and 
check out the circuit.  I am glad I didn't get rid of it because I 
figured out how it opens and have checked the circuit.  What surprised 
me was to find a matching transformer in the vertical part of the mike. 
 Now I understand how a 1.5 ohm magnetic element can be used on a 
Collins high impedance input!.

Anyway, after checking it out I am now interested in restoring it 
cosmetically.  The mouthpiece cap has several scratches on it where it 
was pried off the mike and they need to be polished off.  Is there a 
reasonable way to accomplish this?  The base has some "sand grain" sized 
dimples in the chrome and I am afraid to rub them off lest they expose 
some worse effect.  Has anyone restores one of these and have any 
suggestions on how to proceed?