I’ve built numerous model M engines, and have never seen a bearing like that. What is the bearing number?
Do NOT pound bearings in and out of the case, that is how you crack the case. The procedure is to heat the case, I like doing it on the gas grill outside so it doesn’t stink up the house. The bearings will just about fall out. Installation is the same, except I put the bearings in the freezer for about 30 minutes, and they go right in without having to beat on anything.