Here's another Scott, a Premier sidelock (best gun at the time) with minimal oversize standing breech, but still obvious:

Here's a later one sold through Greg Martin auctions in 2006 that could be considered intermediate?
Many makers' guns are like this:

...and here's even a William Evans best quality sidelock ejector 12-bore with something similar going on:

But of course, all sloppy workmanship done on the cheap...