I wouldn't use loctite here, as it would be difficult to remove the handle at a later date. It is challenging enough to work these screws when they are clean. There is no reason why the original extra screw wouldn't lock the set screw in place on a good handle on a good shaft.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission