Ok, call me foolish if you wish, but I recently bought a rather worn Marlin 1898 12-ga for a very small sum and proceeded to replace most of the internal components with those of a Marlin Model 21 that were sold as a set. Everything appeared to be functioning as it should until I installed the ejector. Doing so causes a jam whenever feeding shells (using empty plastic and brass hulls to check function) from the tube as they are not seating properly on the bolt face, not lining up with the barrel, etc. I’ve read that these ejectors can cause issues and frequently break for this family of shotgun, but why this is happening is a bit of a mystery to me.

Any suggestions for fixing the issue from someone with experience with this family of shotgun?