You can't go too wrong on a $65 cab ever. Paige is right though, it would be expensive to put back as a dual monitor Nintendo. Everything is expensive in this hobby though.
+1 for both dmckean and Paige. You would be an absolute hero if you could manage to restore that back to a Punch Out. However, you would probably have to trade a couple years off your life to do it.
Hope you get it for $65. That's totally worth it for the CRT alone.
If it were me, I'd spruce up the cab and make it looks nice. Then mount a 42in TV vertically in it and play vertical classics on it. You could keep some kind of Nintendo theme on it so it keeps it legit. Just don't hack up the cab in the process. I wouldn't feel bad, you didn't convert it in the first place.
Set the CRT aside for another build.*
*I would normally never advocate that a CRT be removed from an arcade machine, but this is one of those exceptions.