Mike,
the ends of the 1969 GTX wheel opening mldgs are cut different than anything else.

1969 Satellite mldgs are close , but still to long to fit the GTX only side trim correctly

I don't remember but I think the Satellite trim is supposed to be below the body line and GTX is above the body line

I've had four 1969 GTX"s over the years and at one time had every single piece of the side trim NOS ( with exception to the right rear wheel opening mldg - I never did find that one).
I got burned by the Satellite versus GTX mldg scam,,,,once.