My 2 cents, FWIW:

You could plug weld your new stainless strips from the outside of the bed using 309 wire.

You'd have holes in the steel bed, you would position and clamp the new strips to the bed side, then weld from outside the bed and grind flush, again, from the outside of the bed.

In the Stovebolt Gallery ~~ "The Orange Crate" 1965 C10 SWB Step Side Build Thread

Inspired to be different. Different in a way of my own, not in a way that others strive.