Difference Between TA7504M and TA7505M

Dear friends, I repaired an obsolete control card, named RTS1 that was installed in a Toshiba governor control system some 26 years ago. I am afraid to proceed with the on-line test because of a discrepancy discovered during the mandatory pre-check ritual. There are five pieces of TA7504M, an 8-pin metal can IC on the repaired card. The same components on the good and working card pulled out from the control system have TA7505M. I am unable to find any schematic diagram or manual for the repaired card. I managed to find the datasheet for the TA7504M but not the TA7505M. Upon further searches, I managed to find a bit more information for the TA7505M. The TA7504M and TA7505M are general purpose operational amplifiers. The TA7504M has several alternatives likes UA741 and their equals but not the TA7505M. Both are identical and their mechanical layouts pin to pin, characteristics and ratings are the same except for two major differences. The TA7504M uses the bipolar junction transistors (BJT) while the TA7505M uses the field effect transistor (FET). The latter has a better offset spanning feature than the former. I guess that the later version RTS1 cards used the TA7505M because of its improved features as against the TA7504M used in the earlier version cards. I would greatly appreciate it if any of our kind friends can share his or her experience to find the datasheet for the TA7505M. And share answering this question: Can the TA7504M and TA7505M be mixed in the same RTS1 card? The good card has all TA7505M while the repaired one has all TA7504M. Thank you and regards. Rockybeer