Hmmm. I replied, but it did not get posted. Oh well. (1) I thought the CS/P2500 were based on the same chips which differ from the 1ru e-mus. (2) I have cleared off the top of my P2500; let me know if you pix of any chips. (3) I like my P2500 and would not dissuade you from getting one if you want, but from what I have seen you have enough knowledge and skills to write the code and have it work: get names, standard song/pattern midi requests, IIRC. Still, it is a fun machine, so if you find one at a good price, you might very well want to pick one up.
The 4 x 4 circuit boards in the CS and P2500 are different in part because the P2500 doesn't have some buttons that the CS has.
There are good photos of a chopped P2500 on line; not sure if you can read the chips from that, though.
Steve