Brent,
I hear you were up in my neighborhood recently but no visit?
The 450 is a pretty standard chambering and Krieger is making 450/458 barrels. AH#2 was a .500 3" and is a hateful thing to shoot but it matches the customers double rifle.
What's fun? Trying to figure out how the original makers did the work....I even bought a microscope to study tool marks for the hints they give.
Jim