Walker's book, "Black Powder Gunsmithing" was published in 1978. At that time there were many production kits being sold. The level of instruction supplied with the kits was barely sufficient to assemble the kit and have a rifle safe enough to fire. Walker's book gave more instructions on wood removal, metal fitting and finishing than normally found with the kits. There was no internet to give instruction. I learned how to heat bend a hammer to align the nose of the hammer to the nipple on my CVA Mountain Rifle. I've posted those instructions a time or two on this Forum. I built a number of tools and accessories from instructions in the book. The instructions were simpler to understand than the build from a plank books that I now rely on.
The price from Amazon is way too high now, forty years later there are several good videos and other tutorials on the net.
I understand the desire to remove all the ugly stampings and engravings from a modern replica. These can be removed, but I would leave the serial number and proof stampings. Perhaps some maker's identification or date of assembly in a place not readily visible. I would hate to see a replica being passed off as an antique. Most of the defarbing will not make the item look like an original. I see the defarbing for reenactors who want to have the most accurate representation of their equipment for the reenactment. I know because I try. My Long Land Pattern Musket (made in India) has British markings. Once one gets close enough, it can be seen that the barrel walls are too thick, the wood is not English walnut and a few other details, but at 10 yards the musket can pass.
We tend to think way too much about what my rifle looks like and not enough about what my gun would have looked in the time period it was in daily use.