Modern Vespa

1980 P200E

I'm guessing this is what a soft seize looks like. The compression was about 100 psi but was nearly impossible to start after it was at operating temperature. I am hoping a hone and new piston fixes this.

I suspect my oil injection is not working as it should.

That's a "four corner" seize. Polish out the scuffs, a quick hone, solve the original problem and you're back on the road.

https://www.off-road.com/dirtbike/tech/dirt-bike-tech-twostroke-seizure-52428.html

The original problem (one of them, anyway) was your head leak causing a lean condition resulting in the seize.

If the bike still has original seals, you may need to replace those. Do a search for "pressure test," which is what you need to do in order to determine if a rebuild is in order.

Clean it up and run it. Obviously fix your head leak. These cylinders are tough and will run for thousands of miles even after seizing a few times...

looks deep. honestly, i would go 1st over. Clean up your cylinder & head-okay to lap it. I do use a 3 Bond liquid sealant there; not factory, but works will to seal a magnitude of sin.