I've always had an interest in the historical aspects of the British trade, especially so the "who made what for whom" question. I've been researching that issue in particular, and the "trade" makers in general (primarily with respect to double rifles) for some years, and the answers differ considerably from "conventional" wisdom.

While I believe that the Isaac Hollis enterprise may have, I've never seen any evidence that W & C Scott, (or Webley & Scott after 1897) ever did so. That simply was never their role within the British trade. Webley & Scott (separately prior to the merger) was the behemoth of the British trade, by a wide margin, and the core business of both firms had long been as anonymous gunmakers to the trade. Put another way, they were the primary source of guns that other gunmakers "bought in" (and rarely, sometimes stocked and finished) and retailed, not the other way round. Webley & Scott made double rifles and shotguns for almost everybody that was anybody in the retail British trade. They were able to provide finished guns, made entirely in their factory, to the cream of the trade (to be sold under the retailer's name) because their quality was up to standard. Finishing guns "bought in" from others was just never in their line.

This is the old conventional wisdom regarding how such things were usually done with "trade" built guns, and, to a certain degree, I think it's what the retail trade wanted folks to think. However, the facts don't support it.

Webley's stated, in their own catalogue, that 90% of their output was for other gunmakers and that such guns did not bear their name, which is true. We know from Webley & Scott's shotgun records, which survive, that the vast majority of the double guns they built for other gunmakers left their shop complete, not as barreled actions in the white to be stocked and finished by the retailer. I can tell you from research into their double rifles (for which records don't survive) that something on the order of 90% of those built for other gunmakers left their shop complete. In other words, they rarely sent out guns that other gunmakers stocked and finished....and they were, by far, the largest supplier of double guns to the British trade.

As for the relative qualities of I. Hollis vs W & C Scott generally, I regretfully have to disagree.