I'm not sure about millennials not being interested in older firearms. They may not be now, but that could certainly change as they like us grow older.
Example, when I was 16 I obtained an Ithaca Model 37 in 16 gauge. My best friend obtained a Remington 870 in 12 gauge. To us, it was all about fast operating action and shells in the magazine. Why would anybody want to be restricted to two shots or worse a single-barrel? Those old doubles were "grandpa's guns" relics of the past that should be hung over the mantel or traded for a pump or semi-auto.
As we got older, we tended to enjoy the history and craftsmanship of older, better guns. My best friend turned to classic Winchester rifles, me towards Parker shotguns.
Working in a museum, I encounter plenty of millennials. Almost all of them are fascinated by the antique and vintage arms held in the collection. Granted, some are surprised that those guns "actually worked," but they have interest.
Remember, our great-grandfathers thought the next group was doomed, then the next, next, etc.
Just my thoughts....
