This gun made by Reilly for Oaks and Co. Madras mentioned a couple of times above, has no recorded serial number and thus the possible conclusions:
-- It was engraved, marketed, and retailed by Reilly but not built by him," or
-- It was built by Reilly but for another firm and thus not claimed (as at least one internet poster has maintained Reilly did for a number of London gun makers)
(-- or of course...the seller just forgot to put the SN in the ad - entirely possible - in which case it was indeed built by Reilly under license).
I'm still trying to understand how the UK patent use number licensing system worked in Britain in the 1860-90 time frame. Daryl gave an idea about how Westley-Richards handled licensing fees in an above post, but the whole subject area is murky.
From the description there is a reference to an "Ellis & Scots Patent" inscribed on the frame (no patent use number mentioned) (assuming "Scots" = "Scott").
-- Who was Ellis?
-- What patent might this refer to?
-- Was Ellis bought out by Scott?
-- If Scott built the gun for Reilly, would he have put "Scott Patent" on it?
-- If Scott only built the action, and sold it to Reilly would he have put "Scott Patent" on it?
-- If so, are there other examples of Scott built actions with "Scott Patent" on guns made by other makers?
-- or did Reilly pay for the patent and build it himself (in which case there should be a patent use number)?
Sorry for the pedantry, but this seems an important detail in understanding who built what component, when, in British gun history. And guns, all guns, Westley-Richards, etc., could and were built by other makers under license in the 1800's. Reilly sold Westley Richards rifles - he also built them himself under patent. (There were probably 50 makers of 1911 Colt .45's made under license...I can provide a list of these makers if need be to prove a point).
Here is the original ad for the gun:Classic full side lock double-barrel 12ga shotgun with Damascus pattern barrels by E. M. Reilly & Co. London marked, manufactured for Oaks & Co. Madras (India). The gun shows 30-1/8” barrels, 46-1/2” overall with stock measuring approx. 14-7/8 from the front trigger to the end of the horn rubber buttplate. The gun shows standard extractors. The water table shows a series of English proofs and reproofs, 2-1/2” chamber, 3 grams black powder, 1-1/8 oz of shot. Proofed to 3 tons. Left barrel marked 740, right barrel marked 719. The gun shows a quality bank note scroll engraved frame with nicely rebrowned barrels showing 90% thinning, correct color old tobacco brown restored finish. The action has been lightly polished a satin grey, the top of the frame is marked “Ellis & Scots Patent” by the release lever. The trigger guard shows an old reblued finish of which the the trigger and other mounts show a 90 – 95% old flat reblued finish. The nicely burled stocks show refreshing long ago and are in very good condition with some small losses and light wear. The mechanism is tight and action good, bore is very good. A quality side lock London gun by a well-recognized maker. Est.: $3,500 - $7,000