I have a pile of 1/4" plywood salvaged from a demolition project. Some small nail holes. 1/2 sheets and some full sheets. If you want some let me know. Easier if you pick it up, but I’ll help you load it.
Also, I have maybe 8 sheets of white pegboard from the same project - good condition.
Also also - in the shop there are 2 pieces of 1’x8’ MDF and 2 pieces of maybe 10" x 8’ MDF. Free to take if you want it, if it is still here and unclaimed in a week or so I’ll put it in the dumpster.