I got a free PB150 off Freecycle last year. Definitely remove the rest of the rubber feet - they never harden up again and they're sticky and disgusting. It takes a number of Q-Tips and some isopropyl alcohol.

IIRC mine has maxed out RAM; but I really don't like that 2-bit (or is it 4-bit?) passive matrix screen. A real POS IMHO.