Rocketman. This is great fun. I have taken a deep breath and I will continue my search based on your advice. I have decided to look for a BV2 BLE. I have a nice Webley&Scott .20 700 so I have BV3 covered. BV1 is unlikley because of cost. As to the use for the gun, I have at least two shotguns for any conceivable purpose so this is a "just-to-have" thing. I do have Mr. Hadoke's book and I will continue to study it as I go about my search.
Again, thank you so much.

Richard Howard