I bought a pretty nice Disston nr. 12 panel saw off of e-bay the other day. The blade was dark, but not rusty or pitted and the handle was pretty pristine. However, the blade was wavy and not nearly as rigid as most handsaw blades I've seen. I think it had lost its tension due to misuse. I contacted the seller and he took it back, but I'm wondering if retensioning a blade is something you can attempt at home.