Don't all industries work this way? Construction has "old work" and "new work" versions of many parts. For instance, replacing windows on a finished house is a different job from installing windows on a house that's still under construction, so they build "replacement windows" and "new windows." We don't demolish functional homes unless they are unsalvageable; we cut into drywall and patch over the hole. The drywall would look bad if you looked at the backside of it, but the homeowners can't see the inside of the drywall and don't care.