Andy,
The pictures, I believe are of a MVVS 58cc. Same engine, made on the same line, just blue anodysing instead of plain or black. Rings are not related to cylinder base gasket failure. You had to have had very high pressure in the crankcase. Maybe a backfire situration. It sounds like it was lunchtime at Hoizon or quiting time when they worked on yours. It is a beautiful motor.

Dave