On post 75 you have a close up of the missing section of oil control ring. That picture also shows the wrist pin clip is incorrectly installed. The bent tab of the wrist pin clip should be pushed against the radius of the piston. Using a cell phone to document clip installation as shown below works well. This picture was taken by positioning the camera into the adjacent cylinder during assembly.
A long, thin flat blade screwdriver bent at 90 degrees in the middle works well to push the clip tab onto the radius if it is not initially installed perfectly. 3/4 inch electrical conduit with a square notch cut into the end for the tab of the wrist pin clip coupled with an appropriate sized socket on extensions are cost effective tools to install the wrist pin clips. I marked the installation tool and the block with a sharpie to help with tab alignment.