That isn't actually engraving or gold inlay... The image was rolled into the receiver and gold plated. Traditional master engravers would make an undercut, not unlike a dovetail slot, and pound gold wire or sheet gold into the dovetailed recess and then either flatten it or engrave and texture it. When I worked at Williamsburg, Lynton McKenzie stayed with one of the journeyman gunsmiths for a week or so. While visiting we had a get together at the home of the master of the gunsmith shop. At that get together Lynton talked about his work and showed us items he had engraved. In more recent years laser "engraving" has become popular... yes it creates an image but it lacks the texture and depth of field of true engraving. The Cost/Price difference is significant across the three types I mention here! Another way designs have been included on inexpensive firearms was through casting... Below is a Purdey that Lynton had engraved.
When I got back to NY after working at Wiliamsburg my father said to me one day "Williamsburg ruined you." It was a backhanded compliment as I had learned a lot about aesthetics, design, proportions, etc. Whereas in the past I'd throw something together while adding an addition to the house, or making cabinets, post Williamsburg I spent more time upfront trying to make sure the design was classically pleasing which seemed to him like I wasn't working on it.
Me myself... I try but am not in the same league as the finest craftsman I've known over the years. Sadly, most of the greatest craftsman I've known have passed away... lost another last week.
View attachment 1167038