1965-66 BW T10-M1 Date Codes

Hi,
Have a question for you experts on BW T10-M1 4-speed
gearbox. My 65, SFM5S275 has an aluminum case T10-M1 and
extension housing T10-M7 dated like follows: (not original for my car)
- Case is marked 6-9-65 in the casting
- Extension is marked F-7-65 in the casting.
Does it mean June 9th and June 7th, 1965 respectively?

Of course, some of you guys know this for sure.
Thanks,
Texas Swede