I own a documented "matched pair". They are Boswell Best BLE, Damascus, Side-lever ejectors. Chris Batha has provided the records for the 2 guns. The first was ordered in 1899 as a Best Quality A&D Side-Lever, Ejector for Sir James Sivewright for delivery to Cape Town, South Africa. 42 lbs, 10 shillings. Price that against a sidelock..

Sir James retired to Tulliallan Castle, Kirkland on Forth, Scotland. He ordered a matching gun that was delivered in 1902.
The matched pair is in a proper Boswell pair case. If you look closely, you'll see where the #1 was artfully added to the first gun and the second gun's engraving was ready for the #2.
I will have them at the Southern later this week if anyone wants to look.

All Best,

Joe in Charlotte