To go from .54 to .58 would require complete boring out of the rifling and more. Freshening is a different process, involves re-cutting or deepening of the grooves with just a bit of reaming in some cases to smooth the tops of the lands. Custom work like boring and re-rifling is just naturally more expensive compared with buying a new barrel. Installing a .58 liner would require drilling a huge hole in there, also much work and I'd be concerened about drilling a .700 hole or so in a 1" barrel. I'm not sure what's available in replacement barrels but that would be my suggestion.