I know what you mean. I bought a 1987 KX 125 a few weeks ago, that had the reed cage and carb and intake off and the spark plug out, and it was locked up pretty good to, so I just said screw it and put a pipe wrench on the flywheel and it broke right loose then I got the cylinder off and it looked exactly like yours does, I put some kerosene and crap in the bottom end sloshed it around and it was perfectly free, but you could still hear/feal a little roughness in the crank, like something in the main bearings or something.
ATC350X,ATC70,1991 RM 250,XR500,TM400,TS400,Foreman400 4X4,Polaris 425 Magnum,ATC 90, 1982 175,1973 Honda Trail 90,1980 CR80,1981 CR80,