Slant won't start!!?!!?!?

I agree that those push-in compression gages are fairly useless. You never know if the problem is the cylinder or your technique. Anybody who has kick-started a motorcycle or pulled a lawnmower cord (old days before "easy-start") knows what good compression feels like. I can feel that on a slant by turning the engine over by hand. Otherwise, try above "1 cyl at time, listen to starter" method. 70 psi sounds like a pretty worn engine, though it should still fire. I recall ~145 psi is factory new and I like to see >110 psi in all cylinders. It does depend greatly on the cam installed.