Short stop, circuit breaker on boat electrical system

My boat has a short stop auto reset circuit breaker which I think is bad and causing some problems with my electronics not working. I bypassed it and they work, so my only logical conclusion. It has a plastic body, but can't find them locally, but did find a metal replacement at Auto Zone. Anyone see a reason the metal one won't do the job? Pictures below. I maybe only see corrosion as being a problem with the metal one. Thanks