Again, I'm not thinking "Store bought/traded for", I'm thinking a poor guy just trying to carve out a living with barely enough money for the farm, and crude family living expenses. I doubt this guy would buy much of anything he or his family could make (or make due without). I feel projects like this wouldbe planned for days of "can't work the field" weather/seasons or as oppertunities presented them selves. The days before radio, TV, Computers, automobile, electric heat, microwave ovens and etc. found folks pretty much shut-in during winter's mos.
Matter of fact; I remember simular situations with the family around the mid 1950's. We didn't buy what we could make. Remember when women sewed, darnd sox? Men would get together to butcher pigs, beef, hand dig a well, hand dig a cellar AFTER the house was built and such? Many in the family raised their own chickens for meat and eggs. Just don't see much of that happening anymore, or at least I don't around here.
And in the earlier days,, I can vision the average joe doing his own horn with whatever he had available and few probably had the lath as you show in the barn when he'd be concerned about affording crop seed more.
(Just my thoughts on the subject)