That would be a rather odd thing to have compression down on that many cylinders. I'm starting to think broken timing chain. But, you said you definitely see the distributor rotor turning right? If the cam is not turning then I don't think (not sure) that the dizzy would be turning either. I'd get someone to turn it over and put my finger on the plug holes (on the cyls that tested 0 compression), just to make sure that the pressure gauge isn't bad (that might be the case). You will def know if theres compression in those cyls with you finger! Just kind of thinking out loud right now, hope some of this helps.
Phil