I ordered my sleeve from McM-C at 6:30 last evening and it just arrived!!!
I was able to push it into one side with my fingers, but it stopped and is too tight to pull out with my fingers.
My first thoughts were to use something like red locktite on final assembly, but I doubt that stuff is designed for the kind of impact forces this would see.
2-part epoxy? I know the vast majority is going to be pushed out, but there would be a small film to fill in the gaps and solidify things.
I am very impressed with this sleeve. Thank you again, magnus718.