Some pins smell of corrosion
Some pins smell of fumigation
Some pins smell of cigarettes
If you can open a pinball door, stick your nose in and inhale a deep breath without collapsing, you have scored a good pinball !
WARNING: SNIFFING PINBALL MACHINES IS A HEALTH HAZARD *** Do not attempt this at home, Nino is an trained expert in pinball sniffing 
I've sniffed a few in my time and some have been more than just a bit whiffy !
