I agree with Sam Alfano that the square graver profile goes way back. Below, I have posted an illustration of graver sharpening from the old Winters school of engraving. Though it is not hundreds of years old, these old hand engravers tended to do things as methods were handed down over the...
I agree with JJ Roberts. The scrollwork shows common characteristics of Japanese work. This gun was probably ordered through a BX/PX in Japan during occupation then engraved locally.
My guess on the engraving would be Bill Gamradt, Harry Limings, or the late J. Ron French. Since the gun is unfinished, it could be an unfinished piece by French.
Go to www.engravingglossary.com. Click on S then scroll down to SMOKE PULL. You can learn a lot more about hand engraving if you scroll through the definitions and pictures.
Whoever engraved your Colt did a pretty good job of working in the style of Cuno Helfricht. I can only tell so much from the photos but when I blow them up as much as possible I see that there is a complete lack of progression marks in areas where the cuts are flared. This leads me to think that...
Dave, It is kind of an optical illusion. Below the head of the hammer there is a supporting ring of wood that is turned from the handle. You can see it on Funken's handle.
To answer your original question, these pictures of European school trained engravers will give you a good idea of how to hold your chisel and how close your eyes are to the work piece.
I have observed that, in general, Belgian, French, and Italian engravers prefer the long square section metal handles while German and Austrian engravers prefer a shorter, turned wooden handle that mushrooms on the hammer end. It is the tool that they are trained with. I don't know what British...
Merlin designed the gun and did the programming of the laser that actually did the decoration. I examined the gun and spoke with Merlin at the NRA convention in 2019. For laser decoration, it is well done and attractive.
My guess is that a previous owner butchered that gun himself. How often have we read on the engraving forums and FB groups some guy that writes that he bought a graver and wants to engrave his own guns without understanding what he is getting into.