Another English watch with a problem. Fusee lever gaining a lot of time. What do I look for?

#1. Magnetism (not likely, but easily cured)

#2. Hairspring problems (quite likely)

#3. About 1000 other possibilities, which can only be more closely defined with additional information about the exact symptoms.

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Steve Maddox
President, NAWCC Chapter #62
North Little Rock, Arkansas
IHC Charter Member 49