As far as I know, the last Wacom driver that works with the Intuos 2 is the 6.2.0_w5, however I do not think that it supports the ExpressKey remote, which is a shame because it is really a nice piece of hardware and I know it does not work with my
Intuos 4 (errata corrige, I meant intuos 2).
You can try and look if they released a newer driver for the Intuos 2, in which case, let me know.
Personally, to "emulate" the ExpressKey, I use a wireless numeric pad with "function stickers" on the keys
https://www.youtube.com/watch?v=8DSNOz1PxNE&t=452sin conjunction with a "daemon" that changes its configuration files depending onn the active windows executable.
Pretty crude, no display and you must find a work to get it to keep position once the rubber pads at its back fall off
(the grease from the hand palm "sneaked up" and dissolved the glue, in a couople of months - I am using a counterweighted parallelogram, reminiscent of some old technical drafting machines ), but it works...
P.S. would you mind publish a photo of your finished build? When I made my first Intuos 2 XL build, I didn't realize that your machine was a functional one until after I bought a first screen... you managed to get it working, and never posted a shot of the completed thing.