Hi Just a few thoughts on this. I"m working on a 3.152 Perkins motor right now. The pistons that are in it have multi piece oil control rings with 5 parts . when I was looking at ordering the parts there was an online tech sheet that said these ring parts had to be installed a certain way. I wonder if you had these type rings and they are put together wrong. glazing is possible but I never had a motor this bad from start up and a few hours from rebuild.
I wonder could there be a miss match on rings to chrome cylinder sleeves i know some perks had chrome and some cast and seem to remember the rings have to match right for the sleeve type but not sure if your motor could have both types fitted. The other thing that might sound stupid, is the muffler full of oil from before the repair and as it heats and revs it pushes it out more. I had a Belarus in the shop once for a guy. I did the head on it. It had been lightly used and started with either due to bad valve seats. when I got it running it slobbered stuff from the exhaust after an hour warming. I thought here we go more problems and the rings are bad as the guy never wanted the pistons pulled or anything else checked. I started thinking and took the muffler off. it was full of sticky goo that was also in the head on removal. so I took a tiger torch, set it in the inlet of the muffler and burnt all the goo out. it whistled like a jet motor for about 10 mins. I put the muffler back on and it never slobbered again. Hope something here will be useful or someone else will know about the rings and sleeves.