I checked for extra play at the rotor and it doesn't seem to be a huge amount. More like a wiggle than movement.
Timing stays in place until it starts retarding itself, will retard 6-8 degrees. Like moving the distributor, the timing moves before it starts to die, not the other way around.
New motor so all new bits related to timing pieces, turning the crank prompts almost instant response from the rotor, no real slop there.
Weird, I guess I'll just try throwing a few parts at it.
Could the springs in the dizzy be too weak to do their job?