The Endurance Package upgrades were pretty extensive, including changing internal bearing surfaces to radii, etc. I'm not sure that the factory could / would do this. You'd have to contact them. Bear in mind, too, that part of the endurance upgrade included adding weight, which is where the full barrel lug idea came from.
If a shooter will simply back off from full power loads a bit, an original 29 or 57 can be expected to last a long time. Replacement of an occasional part might be necessary, at most.