There’s a LOT more slow work and hand tool use in a handmade guitar than in production firearms, with the latter, even in the “good old days”, better suited to assembly line construction. And, Martin guitars were primarily handmade back then. Not so much now. Today, they’re assembled out of fabricated components, using synthetic production glues and finishes, as opposed to hot hide glue and French polished shellac or spirit varnish.
A comparison today might be made using a luthier built guitar. There are makers today who build replicas of pre-war Martins, if that’s your thing. Prices range generally from $4-5,000 on up.
What revolver today can compare in terms of “craftsmanship”, if that’s the right word?
Maybe a good modern revolver comparison might be to a Korth or Manurhin MR73? (Thinking Ratzeburg Korth or Mulhouse Manurhin). Modern iterations of either make price out starting around $3,500.
Maybe that’s an interesting way to think about the point made in the OP?