I can’t say for sure, but one of the tricks I learned was to test my compression once, then again after squirting some plain old 30 wt motor oil in through the plug hole and testing again.
If the compression jumps up, then the oil is helping the ring seal and yes, you’re not getting a good seal between piston and ring.
Aside from that, there are too many unknown variables.
I’d suggest buying a second motor anyway as they vary quite a bit from one casting to another.
You never know when you’re going to need a “B” motor, just in case ;)