Harris:
At the risk of starting an interminable thread, may I suggest that the "best" has already been achieved. For bench-made guns, the Westely Ovundo, or Woodward (Purdey) are beyond reproach. For sheer armour against all the slings and arrows, the Browning B25 (Superposed) is arguably "best." Without knowing your purpose, why try to re-invent the wheel? You can't make a Fabbri. You don't have rights to a Woodward. And you can't do better than a B25. What's the point? With all kind respect...

Kensal

PS: I know something of the "highwall" or Winchester Single-Shot rifle. You do good work.