That would be normal.
With key in run position....
Battery negative to coil positive should be at or near 12V
Batt negitave to coil negative should be at or about 12v unless... The ecu is grounding that lead when the engine is not running. What I don't know... Does the ecu act like a point ignition when the engine is not running?
In a point ignition the engine could stop with the points open or closed. If it stops with the points open the batt negative to coil negative will be at or near 12v. If it stops with the points closed the batt negitave to coil negative will be at or near 0 volts.
Measuring acrossed the coil terminals will give you various results depending on the state of the ecu / points
