Hi,

I am in the process of cleaning and restoring an old
KW Vanguard transmitter which by the colour of
it, says it belonged once to a very heavy smoker.
I tried all the usual methods to remove the brown
tobacco film, it was so stubborn, it resisted everything
from washing up liquid to isopropyl alcohol (rubbing alcohol).
I then tried household ammonia - fantastic!
It removed all the brown stains in seconds.
One word of warning though - I would recommend doing
it outdoors, the ammonia stinks to high heaven!

Theo