Games like Red Dead Redemption have kept cowboy era guns in the consciousness of today's youth. Same is true for WWI and especially WWII weaponry.
Also, channels like InRangeTV and forgotten weapons on youtube keep a lot of exposure on older guns.
For instance, anyone into assault rifles should be into the Henry/Winchester (and the M1 carbine) because they are the original assault rifles.
In range TV has done a whole series on lever guns that anyone into modern military or defensive guns should find interesting.