Larry,
ALL Darnes built post 1964 came with the highest level of proof, regardless of chamber length. I've seen that movie, Larry. But, a 3" chamber Italian gun is ALWAYS going to have superior proof. Period.
No, I'm not over looking anything. However, superior proof doesn't seem to have been a feature of the old Snipe guns, likely a decision made by the importer. I would have seen a few by now, if they had been, I would imagine.
What anyone is pushing as far as ammunition goes is irrelevant to most guys with doubles, in my experience. The heavier and faster stuff the best?
I guess I missed that memo. I have a pump or two I could feed the 3" stuff to, were I to need to do that. I don't.
The Webley is as strong as it needs to be, Larry. Neither of us, in the years we have left to hunt, would be able to hurt it, even with a 1 1/4oz Pheasants Forever load chambered on a -5 degree day every now and then. With a spreader loaded in the full choke barrel, it could pass for a grouse gun, not the highest evolution of that class of gun, perhaps, but, one hell of a lot closer than the NID you sold.
The Webley is a typical, late 20th century English boxlock, built for the rest of us. The NID was a late 20th century American boxlock, built for the home market. I'm not sure how it would have faired had it been exported to England, or, Europe, but, I wouldn't have tried that on my dime.
The Webley is a higher quality gun, in any way you want to compare them, finish, engraving, ejector mechanism, wood, whatever, which, is kind of what I stated 4-5 pages ago, or so. You keep prattling about how the NID can handle those big, hot, loads, which, you also noted, you don't use so much anymore. True, the Webley will eat up more of your pension money, but, it will sell for more, should you decide to do that.
There is no alternative to those facts.

Best,
Ted