James, I suggest that you go to our main web page
www.parkerguns.org and on its left side is a list which are links to other pages. Click on a few and I think it will answer 90% of your questions. In particular look at "Parker Identification", "Parker Grades" (pictures will solve many of your most basic questions), "Technical Information" and look over the FAQ link too.
I am confident these pages will get you well on your way.
If you tell us where you are located (State will do) maybe you have a "qualified gunsmith near you that someone can post or PM to you?