The hollow lugs were a feature of the early Pythons. In the past on this forum there was much discussion on when that feature was discontinued.
The likes of your gun will never been seen again. Do you know how to pre-index the cylinder when closing it to avoid a turn line? Hold back the cylinder latch and 'locate' the cylinder so that the bolt only contacts the cylinder notch leads as the cylinder is closed. Rotate the cylinder in a clockwise direction after closing.
A properly timed Colt will never exhibit a cylinder turn ring if it is always pre-indexed upon closing. No other American made DA can claim this.