I have both a repop on my 72, and an original for a 69.
There are minor stamping differences for 67-68.... but my 69 tailgate is OE and has the same stamping as the early gates.
The repop is thinner, and has all the stampings consistent with the 69-72 gates, except there is an inside lip that follows the perimeter which is more shallow and not as pronounced as an OE gate.
The inset portion that spans the length of the outside (where the latch handle is located, also has a stepped lip for OE, while the repop doesn't have that lip.
here's a thread on the matter:
https://67-72chevytrucks.com/vboard/...d.php?t=523850