And people wonder why I don't trust "rated for" on anything anymore.

My 10% guess was really just a wild swing in the dark, so I feel your pain. I put a simple pressure gauge on my suction line and found out my "instinct" was basically a coin flip. Now I just glance at the needle instead of lying to myself about knowing what's happening.

Wait, are you SURE it's a fake just from a font mismatch? I've seen legit first editions where printers switched fonts mid-run, especially in the 70s when they were cutting costs, so a library copy might not even match the first printing exactly. Honestly, checking glue and paper is smart, but it can fool you too, since some real editions used cheap materials that mimic fakes. What did the signature look like under a magnifier, and did you check the seller's story about where they got it? That's where I'd put my money before calling it a clever forgery.