JPK-

Yes I know that sleeving involves the removal of the ribs, and I was noting the relevance of Bramble's comment on what you said...

"...The barrels need a trip to John Roberts in England or one of the good barrel guys here for TIG welding the seams. Then good buffing and a re-black with touched up engraving and you wouldn't know the barrels were sleeved..."

It would not likely be prudent to take these sets of assembled, regulated, fully built barrels for such a treatment.
You'd have to nearly completely take them apart to accomplish what you were suggesting.
That could only be attempted if the sleeve job didn't employ any kind of solder where the new barrels met the old 'stubs'

That would be very expensive!

My comments on HAZ and stress can be taken as one wishes.
Just pointing out the engineers perspective on weldments of dissimilar unknown materials and HAZ related stress/stress relief.

Cheers
Tinker