aircraft components and nicotine/tar

[four_two]

Can anyone provide me with any on-line sources of the effects of cigarette smoke on aircraft components.
Not so much now, but when smoking was the norm in passenger aircraft I well remember problems caused with nicotine/ tar etc. For instance nicotine restricting the pressure bungs where cable runs exit the pressurised cabin. Some instruments being clogged up, outflow valves.
I need to provide an on-line cite to prove to someone that these things can happen.
Thanks.

[Perrin]

In days pass when most of the passenders smoked we used to take the outflow valves out of all the a/c to clean them with industrial au de cologue it was like tar, and very hard to wash off.
Used to clean the instrument glasses as a film from smoke made the readings dark.

[mono]

Used to be a lot easier to trace a pressurisation leak though!!

Just look for the brown streak somewhere on the fuselage. :}