SE's used a separate tail panel trim piece but they were painted argent. Post a picture of the trim piece you are talking about.
R/T SE or R/T with A63 get that trim panel & whether some choose to believe it or not at least some of them came from the factory painted black....
I bought my R/T SE in 1975 from the 60 year old original owner.... I didn't question him about the black trim panel cause it wasn't the big question then that people make it these days.... The car was basically untouched...
My uncle bought his 70 R/T SE new it too had a black trim panel..... This has been discussed many times, I find it funny that so many experts who weren't even born when these cars were built have indisputable answers....
The final argument there's no part number for a black trim panel.... Well I can show you dozens of assembly line parts that don't have part numbers...
End of the day you won't change peoples minds....