I am currently experimenting with crubber.  Finding sheets of cork that isn't made of compressed crumbs in the sizes that I need for this is cost prohibitive.   I am hopping that standard cork grease will work on the crubber.  I considered the o-ring idea but my design and build are not precise enough for that.  I also limits the surface area that is in contact between the sleeve and the body.  I am also experimenting with both internal and external sleeves.    

I bought some small latches similar to what Duck showed above that I will add if necessary.  With the length and weight that is very likely.  

--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.