Do all Darnes have short barrels and were any ever made in a trap/pigeon configuration? That missed pair of 28s with 29” barrels would haunt me too.
They could be produced how ever you wanted them.
What most of the critics do, is examine a single sample, often retrieved after one of the wars, often a very low grade gun, perhaps even a copy of a Darne, and then proceed to make blanket statements about guns that were in production during parts of three centuries. A lot of the sub gauges produced for James Wayne and Stoeger were built with 25” tubes, because that is what most of the writers were telling people that is what they wanted. They didn’t, (but, they didn’t know that, either) and, as a rule bought what was on the shelf at either importer.
The guys at the bench in France loved the guns with longer, and heavy wall barrels. I was offered a turn of the century custom R grade, a 12 with a wide, flat, file cut rib, and 30” tubes, but, it was the end of the trip there, and I was out of money.
Best,
Ted