"Sam Goldwasser" wrote in message
As they say: "If it ain't broke, why fix it"?
What's wrong with an old supply if it does the job? Unless there are
problems, or you are seriously expanding it, a new power supply won't
make it run better.
Either way to answer the question, polarity doesn't matter for the
pushbutton, any momentary button will work, all it does is connect the two
wires together when you press it.