CGB wrote:
Nexus 7, you've been a big help and I appreciate your responses. How does
one find out if a replacement breaker is designed specifically for my box?

You can take your failed breaker, and whatever information is on the
box from labels, logos, etc. with you when you go to the store. Knowing
only the probable age of the box, you're unlikely to find the breaker
at the local Home Depot. Even if they do have it, it is unlikely that
you will find a store employee who can authoritatively tell you that
the breaker will work with your box. In that situation, you going to
have to go to an electrical supply store or hire an electrician. Now it
may turn out that the box was replaced subsequently, or it is a GE or
something that is still around, and you find a drop-in replacement for
it. So go ahead and look for it. Just don't pop it in until you're sure
it is made for the box.