What problem is it that a stainless steel gun can solve ?
It's hardly difficult to look after one that can go rusty if neglected. As can SS things, these aren't made of marine grade alloys that can survive years at sea without maintenance. Oh no. They are not made of such stuff.
Give me a shotgun made with good old steel, chrome plated bore, nickel plate outside, and I'd say thats pretty much as good as it gets.
As for Longthorne tying down their design with patents, well maybe somehow they have got away with that, but I suspect it would not stand up to the most rudimentary challenge. Not that that is likely, because it is an enormously expensive way of making guns, last time I looked it took a 14 kg billet of exotic steel to make the barrels for one shotgun. The chap, operating the factory, on the video seemed proud of that. Perhaps he would have been even more chuffed if it took a 28 kg billet.
The rest presumably swarf.
If I had the sort of money to buy such a thing, I'd rather it went to a "best" gunmaker, then distributed to the employees, apprentices, subcontractors, engravers, stockmakers etc. sustaining a long tradition of skills, tradition. employment, etc.
Rather than go to somebody with the resources and ideas to blow away all of that with great CNC stuff, but no soul, and minimal employees. I'm sure it is a superb bit of sterile engineering, but utterly missing the point of what makes a shotgun characterful. And affordable. And sustains an enduring tradition of craft, skill, employment, and heritage.
Even their nice stocks are churned out on CNC. The man was complaining that decent wood was getting scarce. Oh dear. Maybe time to learn how to replicate wood with polymers, and get improved performance. Then slap on a coat of some pseudo coating to please traditionalists. Oops, already been going on for many years elsewhere.
Even the "engraving" is just done by laser. Original designs by artists commissioned, then copied into the machine laser programming. Well that is what I have heard (from an embittered engraver who worked on a few in the early days and saw her art ripped off after the first few).