Backyard Professor: 16: The Incredible Book of Abraham Scholarship of Paul Osborne
That was a fine job, outstanding!
NOW, without any further ado, I would like to come to the point about those chisel marks in the jaw/snout which was removed from the lead plate by Reuben Hedlock. First, let it be understood that the tools used by a 19th century engraver are single point and have a variety of different tips in which to work the material in order to shape and carve the design to the desired shape. Here are some examples of such tools:
19th century engraving tools
Now, here is an up close image of the snout that was carved out of the lead plate -- please pay particular attention to the notches that appear like teeth in which the canine mouth was removed:

So what are those notches, exactly? Why did Reuben Hedlock carve them and leave them there rather than smooth out the jaw?
Let it be understood that the reworking or removing the lead material from the original snout was below the surface and could not therefore transfer ink. The printer's plate with all its details and hidden imperfections was known only to the the person who made the plate, in this case, Reuben Hedlock. He is the only person who knew about those notches. Nobody else would know about those notches until I revealed them on this message board in December 2017.
The original snout did not have canine teeth, so please don't let that cloud or confuse the issue. Anubis is not shown to have teeth in Egyptian art. But Reuben Hedlock pulled a fast one, a little secret known only to him! Allow me to explain.
I give it as my opinion (as someone who knows) that Reuben intentionally made some six notches in what was left of the original jaw to resemble the teeth of a canine in order to honor the original drawing in which he was not permitted to portray. Reuben Hedlock secretly included those teeth to honor the memory of Anubis! It only took a brief moment. It happened very fast and it was over. Nobody would ever know he did that but he did it intentionally for this very reason. Hedlock liked dogs and wasn't about to let this dog completely die!
I hope that readers here can accept this answer. I believe it to be true.
Thank you
Shulem