The PW50 is oil injection so as long as there was oil in the oil tank you are fine. You didn't mention if there was or not. The fact you were able to run it hard for a while means there may have had oil in it. Also Seafoam has lubricant in it so that would have helped if there was actually no oil in the tank.
In any case, the damage would be with the crank and rod end bearings...and of course the piston and cylinder. I'm not sure what compression a PW50 is supposed to be at but 120 psi is low for a bigger 2 stroke. It may be fine since it's a low performance motor. (Edit: I did a quick internet search and 120 psi sounds pretty good.)
Check for oil in the tank. If there wasn't any there I'd pull the cylinder to check the cylinder bore, rings and piston for wear. Also check for any slop in the crank or rod end bearings. If you did have oil than you are good to go!