Is this the 99/44 Deerfield?
No, it's the predecessor to the Deerfield.
Don’t see how it could be
If the firearm is manufactured before 1970 ( in 1970 tomorrow) it is C&R, which states 50 years old, plus other reasons posted above in the link.
This is a 1976 per the serial number
Think I've got a taker, but still welcoming back-ups.