Handspring Hard keys

The hard keys of my Handspring Deluxe (8mb, black, Palm OS 3.1) started to fail some time ago, at the beginning it happened sometimes the datebook button didn´t work, now is not only datebook button but up and down button too.
up and down hardkeys are very important. I´ve searched hard for an application to reassign hardkeys but the closer ones to my problem remap only a damaged power button not the other hard keys, other apps deal with remapping soft keys to launch applications, not the functions of the up and down hard keys.

Please, if someone knows a program to reassign those hard keys up and down functions to other soft keys even a stylus solution, or a DIY repair (because I don´t want to send it to Palm) please let me know, thank you

Juan