[Leica] spot in shutter curtain (burn?)

[Stefanos Kaxiras <kaxiras@cs.wisc.edu>]

Hello all,

I just noticed a small spot less than 1 mm wide,
above and to the right of the white circle
of the shutter curtain in my (fairly new) M6HM TTL.

It wasn't there before and I suspect it might be a 
small burn. 
It doesn't go through the curtain (I can't see
any light coming through) but I haven't verified this
with film.

I have a few questions I hope you can help me with:

1) If it is not a burn can you think of anything else
it could cause a damage spot on the curtain?

2) If it is a burn, is it likely to deteriorate into a 
hole ? 

3) The spot is grey and it reflects some light (it is not
mat black as the rest curtain). Could it affect metering?

4) Should I replace the shutter curtain? What does it take
to replace it? Is it a major repair or something that can
be done easily and quickly ? Will a repair affect the rest 
of the camera in anyway (externally or otherwise)?

Thank you,
Stefanos.