If what you have is working, I wouldn't mess with success. The charging system is pretty decent when maintained (check your brushes) and the TCI ignition is solid, so no real advantage of doing the Pamco before it's time, but you might want to find the hard parts you'll need to go Pamco if you intend to hang on to the bike. Even if you don't those parts will be worth the money in a horse trade with someone who knows. You could upgrade the coil to one that will still be compatible with the Pamco and maybe gain a hotter spark and some efficiency.
You do have the luxury of shopping around for what you want as long as what you have is still running. Is your intake and exhaust still stock? Front forks?