Hi,
Thanks for responses.

https://www.gmheritagecenter.com/do...hevrolet-Trucks/1961-Chevrolet-Truck.pdf

If you go to page 52 of this pdf it will tell you it is plywood.

I think the gentle raising of body is best idea.

"panel fan" It's interesting your truck has two layers of 1/2" where mine was one 1" layer.
How many skids on yours? It says five on that pdf page, but I got extras with mine I think.

Pete

Pete Geurds
1961 Chevrolet 1-Ton Panel Truck