Do you have journaling turned on? If so ARCTOOLS can get the deleted records back, assuming you still have the receivers on the system or on tape. I can send you a demo that will get your data back.
If not, your only alternative is to restore the pre-purge files from tape and figure out how to weed out the duplicate records.... not an easy task.
Check out http://www.arctools.com for more information or send me an email at email@example.com and I'll call you directly.
Purge and Archive your BPCS data without programming with ARCTOOLS (tm)
Add the archiving feature to your existing purge routines without programming.