Beautiful work Mike, and a veryb nice origijal English rifle.
Dave,
I think you have it for sure.
German barrels were held in high regard in England, and it is not uncommon to see a German barrel stocked up in England in either English or German style.
There was quite a fad at one time for Germanic rifles, (In the UK)and many well known makers, (inc. Twigg) produced German "jaeger" style rifles.
I believe Mike's photos above are one of these.
Really nice rifle and begs to be shouldered!
Richard.