Earl,
Welcome to this forum. One way to learn about engraving is to visit the engraving glossary. Just click on the word Glossary in red above. Also my book American Engravers-The 21st century is full of information about how gun engraving is done and includes quite a bit of historical information on the subject. You can order the book at this link:
http://airgraver.com/american_engrav...st-Century.htm
You are absolutly correct when you wrote "I am amazed how little the collecting community understands about engraving." Collectors frequently misattribute who engraved a gun. Even the experts on specific guns who know every minute detail of their specialty often misstate styles, techniques, and the age of a gun's engraving.
I have added images below of a Walther model 9 engraved by the contemporary German engraver Claus Willig. The auction site that listed it stated that "C.Willig must have been high ranking in the Hitler regime to rate such an engraved gun!" Claus was born in 1939 so he was six years old at the end of the war. So much for their expertise about engraving.