"T"- I used a small wire wheel on top 3/4" of bore and then used a crocus cloth-cleaned up so it would hit TDC-it was "locked' at about a half inch from TDC. I'll take pix in AM. It still would not rotate and I could not see what the obstruction was-took the cover off the fan and it now rotates but I still did not see what the obstruction was. Stay tunned.That's good as the marks are there. That cylinder looks kind of nasty. You are going to have to clean what you can up top , remove the rod cap and push that piston out to clean up the cylinder, rings and piston. If it is dirt, things probably aren't going to go well unless it sat with the plug out for awhile. Maybe rust? Mark if you want, use that smart phone camera as that is your best friend when you are not used to having something apart.
At TDC as determined by screwdriver resting on piston. Lock the setting in place then crank a few times and bingo, rocker is flopping around?Possible that you are out of time? At what point did you set the lash?