it's a cool bike, but not the rarest of finds.
it's up to you. if you plan on selling it, it's worth more without the motor, unless you've got exceptional building skills. slapping on a stock china kit with the ugly football tank won't bring the buyers banging down your door. if anything, you'll get the same amount of money without the kit.
if you're keeping it for yourself, do whatever you want, it's your bike, but as 2door said, don't drill into it or weld on it. i've built plenty of old bikes, but everything can get put back to stock with nothing left but a few scratches.
the only old bikes i weld on are tweaked or cracked frames.
my advice is clean it up, find parts for it when they come up cheap, and keep it as a pedaler.
find another bike to motorize. unless, like i said earlier, you got some skills to make it really stand out...
