Ken1,
That's a decent gun you cited, with coil spring sidelocks. Nothing to be ashamed of there, and y'r right: a lot more 'shotgunnery' than the contemporary American guns, albeit our guns are stout -- but very often somewhat clubby handling.
Altho this is a oft repeated topic, used Ugartechea Model 30's turn up in the market, Cabela's at Dundee having had a half dozen recently in all sorts of configurations.
Mostly they were straight hand game guns, but some were light and slender as in the ideal upland style, while a couple were 12ga Three inch guns that were heavily built and magnum proofed. the 'asking' was around the 800.00$ USD mark.
The usual caveat: yes, one may get a set of soft firing pins or improperly hardened sears. It happens. There are able smiths to remedy such probs, and if they go thru the gun and corrct anyother deficiencies, you still have a gam-y gun that will give good service and one that strongly resembles a half-way decent game gun. Just opinion and I expect everyone else to have theirs.
More opinion, based on experience and actual use: If a person wants a rugged waterfowling double the SO Model SxS imported by DeHaan will hold up in the worst conditions and usage -- tho I am not on saltwater, so can't speak to that. Examine the technical specs and you will see why theyare dang near weather proof.
All I do to add to it is romove the stock bolt, and fore arm iroons, soak the wood thor'ly with spar varnish, heavily wax the metal, and reassemble when the varnish is almost set hard.
My last SO is still doing duty as the club's trap boy and utility gun, is smoothly tight, and hasn't malfunctioned to date. As in all such reports, your milage may vary, but that's the latest on that particular gun.
This topic always draws advice and over the years it just gets better an more realistic. For sure, i do belive I'd add the NID to the group of rugged guns, tho I've never been taken by their aesthetics, myself. They dom however, certainly have the persona of a quintessential American hunting gun.
Lots of fun to read such strings and see what's 'new'in the common experience. now that the seasons are hear, happy powder smoke and falling birds to all hunters and their dogs.