Wood bed woes

[Ultrasummer]

I'm doing a wood bed kit for a 1968 stepside C10. (shortbed). I ordered the wood first from Brothers and have been staining it. I see that LMC has different choices for metal strips. I wanted to wait and see what the finished wood looks like before deciding on what finish I want for the metal strips. LMC also has the 90 degree metal strips that run lengthwise along the corners of the bed. Upon removing my wood, when I get to those old rusted 90 degree pieces, it looks like they are spot welded in place. So my question is, did the factory originally spot weld those in or is this someone's handy work from a previous owner?