You said you switched the wires on the coil. It sounds like it was already correct. Since its a "positive ground" system the positive terminal on the coil would go to the distributer. It would be the negative terminal going to the distributer on a negative ground system. The coils are wired differently inside for negative and positive ground systems. You need to make sure you have the correct polarity coil. It will run hooked up either way and probably would have nothing to do with the hard starting but it will have an effect on the ignition system. Here is a very good article explaining why coil polarity is important.
https://mgaguru.com/mgtech/ignition/ig104.htm
When you do your compression test again make sure you hold the throttle blade open. Air needs to be able to get in there and fill-up the cylinder to get an accurate reading.