I posted about 2 weeks ago re: replacing a circuit breaker. I got some
excellent advice, especially from Nexus 7. I got a replacement for it at
Home Depot. The only difference between the old one and the replacement was
that the screw where the wire attached was at a slightly different angle on
the new one, actually making it a little easier to reach with a screw
driver. I made the replacement. Technically, it was quite easy. The
circuit worked. Forty-eight hours later, the house hasn't caught fire!!!
So, I guess all is well.
Many thanks to all for their advice.