Xena,
Can't be right all the time right?

It should/could be plywood or someone dropped something too hard and damaged the original floor and went with planks.
(You don't just run into HD or Lowe's and get a 12 ft sheet of plywood.)
The skids do give the floor a similar appearance to a pickup bed.
Our trucks have been around a while so strange things turn up.

btw: Anyone else have 10,000Lb GVW plate on their panel?
It has a LOT of leaves in the rear springs!

Pete