Mismatched chips probably won't work. I'm a little confused with the labeling however as I didnt think that there were more then one build actually made into chips for any one system. I'm not at home, so I cant look up the delta between 40.63 & 40.68, but it was probably pretty minor. We used to get new builds every week or two from Commodore, and run them with superkicks on our 3000's or the 3640 set for superkick on the A4000's.
-Tig
