I've used pinball pimp stencils and I think I asked him how long they would stay good and I believe he told me up to six months but I think it's best if you lay them out flat rather than leave them in the tube rolled up.

You can always email Jeff at pinball pimp he's pretty good about answering any questions you have

Glad to hear you got hold of Jeff he's a great guy and his products are awesome so I think you'll be real happy with them when you do finally use them.

Good luck on repainting your game and make sure you post pictures so we can see it