Omar:

You've said you have the Orcad schematic and PCB files. Am I getting the impression that hardware changes are in the near future?

If so than as Andy has suggested it may very well be far more productive to switch to a another chip platform that is better supported. You may also find that the opportunity to change (and due to whatever time has passed since the original development till now) that yu can find some other part(s) that may even eliminate some other parts and ICs on the board that now end up integrated onboard the replacement chip.

I suggest this because I've been in the place you are right now and found very quickly that it was far more productive to not spend time struggling with old and unsupported stuff and quickly switched over to SiLabs parts. In my case the cost of the MCU turned out to be a secondary consideration in the whole mix of things. Making that change allowed the PCBC to be redesigned as to so much reduction in component count that the product went from two very crowded boards in a sandwich to one not so crowded board.

Michael Karas