The Original Quality grade of the gun is at whatever level Piotti made King #1's in that time frame. Use of the term "best" requires a number of modifiers for modern guns; it is a very complex question and not good informantionally to answer as a simple "Yes" or "No."

"Shot and Regulated by XXX" is a way of adding Brand Value to the gun. In short, it puts the Jeffery reputatuion/brand value behind the gun. In the '80's UK, Jeffery may have had a bit more BV than Piotti.