If I may offer my two cents:
Compression gauges are the least accurate way to determine 'engine health'.
Leak down tester (if it doesn't run)
Vacuum gauge fist (if the thing run)
everything else.
Also setting the points gap with a feeler gauge is the least accurate way to set the gap. Many manuals state that you need to use a dial indicator and adjust the arm with that. The reason being worn points are not parallel and with a feeler you are setting the minimum gap from ridge to ridge, not the absolute distance.
My 42 Ford runs better when the point are set with the dial indicator. Brand new points might be the only time a feeler is going to be accurate as the electrodes are still parallel.
A dial gauge and mounting base is $20 and can be used on the differentials, transmission, engine, etc etc lots of places.
