"Sleeving" is when a shotgun has its old barrels cut away and new barrels placed into the monobloc that remains after the old barrels were cut away
"Resleeving" is when a set of shotgun barrels that were previously sleeved (as above) are sleeved for the second time (or third time and so forth) in the method described.
While WE are getting so technical cutting off a set of barrels does NOT leave a Mono-Block, unless the gun was originally built with one. By Definition a mono-block is when the breech section is made from ONE (Mono) solid piece. Cutting off the barrels does not turn a chopper lump, dovetail or any other type of breech assembly into a mono-block, the Brazing seams are still there.
If you want to "Correct" someone else's terminology be certain you have your own Ducks in a Row.
