isnt the MBR and the partion table independend? Meaning they would have been screwed and not just because of the other one

. theoretically only files using the no longer avaible space should be affected. maybe just doing a chkdsk does fix it. I mean losing 8mb of partion wont hurt, but losing the file index while rezing would

. anyway you should do a disc recovery backup (containing mbr, partiona table and indecies of the file system). After that you can try almost anything, just make sure you can boot from another media to do the rollback on the disc (overwritten files content will however still be lost)