Those are Excaliber grips.
Very well made and fit good in most peoples hands.
Screwed together from the side and also have 2 pins to mate each side together with the other.
They also do a bonded Ivory as well.
Colt did NOT make those grips.
They farmed them out like other things they did in the past.
They were found on Python Elite's, however, they were not mfg by Colt.
The Python grips Colt sells today are not made by Colt either. That's why when you order them they tell you they are waiting for a new batch to arrive.
FYI: Colt Elite grips were made be 2 different manufacturers.