I think your assumption of .016" gap and 30° dwell probably is pretty close, although probably you would find a little higher dwell. Yes, rough/pitted points will cause a wider gap when set with a feeler gauge, and will result in a higher dwell angle.
I don't have any pictures of good/bad parts as you asked about, but maybe I can find some. Absent pictures, look for the following:
Irregular or black, fuzzy lines on any bakelite/alkyd/plastic parts are a bad sign. Usually those indicate cracks, but they may be surface carbon-tracking. Replace the part.
Rotor: no cracks or carbon tracks in/on the bakelite/alkyd/plastic part; center contact should be smooth and shiney; rotor should be tight/snug on the distributor shaft; "finger" tip may have some roughness and carbon, but if it is not loose, roughness is not a problem. Make sure the bottom of the rotor below the rivet is not discolored. Discoloration indicates insulation failure.
Distributor cap: same as the rotor; also, the center carbon button should be smooth and shiney- a little flatening is not a problem if the carbon is not worn down to the metal sleeve. If the button is dull black and 'fuzzy' looking, the rotor contact has been arcing and the cap and rotor both must be replaced. The wire terminal sockets should be clean and tight, but corrosion can be removed. Don't try to remove roughness from the rotor end of the wire terminal- the roughness is caused by the arc there when the spark plug fires. The roughness will only return after a while, so save your time and energy on that one.
Points: the contact surfaces should be smooth, preferably shiney, but used points will have a frosty look. A bluish color, like hot metal is just that- the points have been overheated, maybe high dwell, but also high ignition current. Pitting and metal transfer indicates a condensor matter, and/or maybe incorrect dwell, depending on which way the metal transfer goes. Look at the spring- should be shiney- any discoloration indicates high ignition current or high dwell combined with extended low-speed engine operation- idling a lot of the time. Usually, discoloration of the spring is the result of high coil current. That can be caused by shorted primary windings or high primary voltage- voltage regulator setting, or no ballast resistor or shorted coil if you have a 12-volt system.
Hope this helps.
Harvester
