don't worry at all. I have sometimes 100 of them and the change in weather, even when stored properly causes movement. Not only the rails, but once you attach 50lbs of parts under and suspend by the edges, it dosent matter how warped it is. That is my experience.
kruzman

I use the side rails from pf's I have de populated, but any wood stock will work but you have to use it with the thin side against the pf. for example if you used a 2x4 which would bee funny but would work, predrill thru the long side of the wood stock because that is the side that bends less, and screw it to the back of the pf. length sticking out the top and bottom dosent matter. I try to get 4 pieces of wood.
So far in my pf experience the pf that is the worst is because of a design error. there is just too much wood cut out in one line, which is safecracker. almost every pf that comes out of the game is warped. 90% of pf will un warp themself when the weight is installed (the parts) and the way it sits in the cab, causes it to flatten out almost every time. the best place to store a pf is always in the game.
I will store pf's against the wall on their sides, keeping them as close to 90 deg, or straight up and down as possible, but they will warp from their own pull. meaning their layers are set 90 deg advance each ply. so if one ply has some crap in it causing it to not be as strong as the others, the pf will twist its self. I go thru every month and adjust them against the wall, allowing gravity to do my work for me. as for twisted pf's, it is important to get the bottom parallel to the wall, that is the bottom edge that is on the floor. then one corner will hit the wall. use books or whatever is heavy so it wont slide and lean it as as much angle as will hold like 70 deg. and let gravity pull it in the direction you need it to go.

OK so who has a nos pf they want to sell me. I havent bought a pf since july I think. definatly need to restock. also interested in cpr and repro pf's.
cheers, kruzman. galesburg MI

if you dont understand how I poorly explained to deal with twists, let me know and I can take a pic