Re. Variac brush repair

A small bit of additional information.  I called Superior Electric in
Bristol CT at 860-585-0600.  The model that I have, #1126, is apparently
something like 30 years old and they tell me that they no longer have
parts for it.  I further asked whether anything similar existed that
might be modified, but was told that every model's brushes are very
different compositions of metal and carbon specific to that model, MOST
unhelpful.  I can't believe that it could be THAT unique, but I wonder if
variac brush compositions are necessarily different than motor brushes
which I might be able to modify.  It would be one a shame to
junk an otherwise perfectly good 2KW variac for lack of a brush.  

>Original Poster: Gary Lau  13-Dec-1998 1211 <lau-at-hdecad.ENET.dec-dot-com>
>I have  a Superior Electric Powerstat 120V/15A variac whose brushes are
>just about at the end of their life.  While my first choice would be to
>simply buy a new set of brushes, I fear this may be hard to come by.  If
>anyone knows if it is possible to buy replacement brushes, please do let
>me know!
>Anyway, I was considering the possibility of repairing the old brushes.
>They appear to be brass blocks with a carbon brush soldered into a notch.
>While I'm sure I could find another carbon brush and machine it down to
>size, I'm not certain about how it's secured in that brass notch, I doubt
>that carbon is solderable unless it's copper plated.  Has anyone else
>attemped such a repair?
>Gary Lau
>Waltham, MA USA