Problems 1965 rear cab supports

[lexteak]

I'm building a 1965 c10. Currently doing rust repair on the cab. Passenger side rockers and some floor patches, pretty standard stuff and I have that side completed. I started on the drivers side, first thing to do replace the rear cab support, I did not do this on the passenger side. The cab support I have is not in the correct shape. The two side (one along the bottom of the floor, the other along the rocker are at the wrong angle. Pretty significant difference, maybe 15 degrees. I have checked parts from 3 different manufacturers and they are all the incorrect angle. I believe one of 2 things are going on. My truck was made somehow with different parts than a standard c10. Or possibly these parts got made wrong somewhere and they are all copying off the incorrect parts. I have some photos detailing the differences. Has anyone else had an issue with 1960 to 1966 rear cab supports from aftermarket like TriPlus? Thanks in advance for any info you have.