NEW Shimano 7 spd HG freewheels are available at my LBS for the princely sum of +-$25. Might also be in your area?
I bought a 14-28 for my old C-dale SR900 that my son now rides, and I bought a 14-32 for my wife's quite vintage Touring Trek.
Not sure if I'd be spending time trying to fix something, like this one, which is in a common touring cog range and available down the street, new ...