Yellowed Plastic caps?

[Daniel Gendreau]

I am giving my new 808 a bath tonight.
It appears a previous owner was a smoker.
The whole inside smells like an ash tray... ;p

The clear plastic re-legendable keycaps (Start/Stop, Tap) have yellowed a
lot.

My question is: Has anyone had any luck clearing up these caps or is it just
a sign of age?

I am going to soak them in water with a bit of detergent overnight and see
what they look like in the morning.

Thanks,
-Dan G.