If it turns over, pull a spark plug wire and hold it near the block.. turn it over.. look for spark. if none.. start 'following the volts'. Check for power to input of ignition coil.. a vom will help with this. many times ignition switchs go south, so a small jumper wire is helpfull when looking for bad components. many times i jumper right from battery to coil, and then move 1 wire / component back at a time to see where the poblem is. Resistors ( if present) are prime problems as the metal filament inside the ceramic can break.. Swich guts are pretty common to go out... Ancient coils go bad... etc.
Feed thru wire from side of distribuitor to points can break, or short to distribuitor body... etc.
Easy to tell if points are opening and closing by seeing voltage fluctuate at input of coil with a vom... battery votls is points open.. lower is points closed. ( lower will depend on if it is a 6v system.. then lower =0.. or a 12v system with a dropping resistor.. then lower just equals.. well.. lower.. depends ont he coil and resistor used.. still easy way to diagnose.. etc.. )
Email if you need help. I've got a NAA and a 660.. both very similar..( electrical wise.. ). heck.. so is my 8n.. etc..
Soundguy