Briggs 31A607 Ring resistance problem

Recently my valve seat exploded into the combustion chamber while the engine was sitting turned off after having been run. When I tried to start it, the chunks of valve seat got squished between the piston and head. The piston surface is now covered with dents from the pieces. Now the engine has some weird resistance in the middle of the stroke when the piston is moving the most. It is almost hard to turn at some points. I believe that the piston either had material be squished outwards rubbing into the cylinder wall, or the groove the ring sits in got squished and the ring is pushing against the wall. My question is whether I should get a new head and see if it’ll fix itself, or just get a new block from the junkyard and transfer the pieces over (intake, carb, fan shroud). What do y’all think?

You have the head off.  Does it appear to be scoring the wall?  If so, it will only get worse and not correct.  You lose compression and burn oil; you'll need a new piston before you destroy the cylinder wall.  Would not hurt to hone the walls while the piston is out.  If the walls are damaged pretty bad... yeah it would probably be easier to find another block.

As for the resistance, something could be bent in there too?  Crank? Rod?

The engine has pretty good compression and the walls are in decent condition. There is one scratch at the bottom of the cylinder wall that I can feel with my fingernail but that seems to be it. When I move the piston with oil on the wall I don’t see any lines in the oil if I remember correctly. I’ll check when I can get home. I’d rather not pull the piston. It’s supposed to snow here on Monday so I’d really like to have it running by then, even if it means temporarily swapping the engine over from my running mower mower. I’d rather not have to do that tho.
As far as if anything is bent, I doubt it. It happened while the engine was spinning down and the only force on it was the speed that the starter could turn it.

The valve seat exploded? That's a new one on me can you show a pic? I personally wouldn't trust a dinged up piston, every mark in it is a fracture waiting to happen and the ones around the outside could pinch the rings preventing them from floating as they need to.

There is not much left of it lol. I only really have the chunks of it that I pulled out of the engine.
Should I just replace the block & rotating assembly with a junkyard one, or should I slap a head on it and see if it fixes itself. The junkyard I asked said that a new (used) block would be $100. I'm pretty sure I can just swap the carb and intake over