Funny really when you think about it. Colt's were originally nothing but tools. The factory learned early on under Samuel to carve the tools up and make them pretty which helped sales.
But they were nothing but tools back then. Even the best master engravers are just scratching up metal with a hand chisel. How deep it gets carved depends a lot of the engravers skills or lack of.
I have engraved guns that have valleys carved deep into the metal...by master engravers. And I have one (now two as I bought a duplicate) laser engraved Piettas. They aren't flat..no one who has actually seen and handled one would claim it was. And frankly as a tool the laser engraving is more fitting in my mind than a hand engraved piece worth thousands of dollars. Hand engraving a 3rd Gen Colt might well be questionable. Adding hand engraving to a Pietta or a Uberti is a waste of time and money...again IMO. Simply because the base guns have so very little value and no history.
Think back to the hay day of the Colt SAA and every cowboy wanting one. Who wouldn't want a fancy six gun? Hand engraved, ivory, pearl and gold or silver finishes were top dollar. They bought ivory and pearl and on occasion an engraved gun...but rarely. Fancy guns or engraved guns were just too expensive for most working folk. I have to think back then, as now, a lot of folks might actually like and want an engraved, PVC gripped Pietta. It is a hell of a nice tool if one has the need...and pretty too. I own a safe full of master engraved, matched pair, Colts, sporting ivory. Funnier still that I think enough of the recent Pietta to buy a pair of them.
Only one I need to please is me, and this pair of Pietta does that just fine. The dollar invested has nothing to do with.