Got busy again, field-work etc, but finally got to shoot the Rigby on the weekend.

After a 'warming' shot into the dirt bank, the first 3-shot group at 50 metres off the bench, open express sights, was a cloverleaf!

Working up with AR2208 (Varget) left me pondering, velocity was a good 150fps slower than that published on the ADI webpage for a 140gr bullet atop the loads I tested. Will have to try AR2209 next. All good fun!

Rigby's were quick to send the provenance: the rifle left their shop in January 1911 in the hands of a Major E.S.D.Goldsmith. The only likely candidate I have identified so far seems a bit early, 104th Bengal Fusiliers, Irish Regiment, so maybe it was a 'present to self' in retirement!

Will keep researching....

The details listed in the Rigby ledger are still correct today, length of pull to anti-recoil pad is still the same despite a recent Silver's replacement, and that magic word "Best" is there as well.
I was pleased to see the 'telescope' was fitted prior to the initial sale, but no details of the optics were recorded.
Interestingly, the rifle shares the weight (6lb 9oz) and barrel length (22 inches) of what was to become the No.3 pattern, presumably after the Kaiser's war, however this example was listed as a No.2 pattern (High Velocity model) at the time.

Should have some time to get back onto the scope-mount issue soon, will post anything of interest.

Thanks for your help all.