Post SAW, many Trapdoors were still in Service and being used for training of the various Home Guard/State Guard units, in lieu of the '03's and Model 1917s that the Guard came home with after WWI.
The Home Guard/State Guard are 'not' National Guard units, but more of a pure 'militia' concept to be brought into play should the National Guard be called up.
They were usually made up with men too old and boys too young for active Service - had uniforms and insignia, performed Drills and were to assist the State in 'keeping order' in the absence of the local Guard unit.
Nebraska even had a vehicle - a Harley - no one has ever figured out where it went.
Their hefty stockpile of Trapdoors was 'discovered' inside the old 'State Arsenal' on the State Fairgrounds a goodly number of years ago, and those Trapdoors walked out of there on a weekly basis until they were gone, thanks to State employees of the Guard.
Matter of fact, they had a 'General's Cabin' where the visiting Officers could stay while in the area, and above the fireplace mantle were two crossed Trapdoors - a'la Infantry Branch Insignia - and when those went 'missing', they went to one of the 'accumulators' of the State Arsenal Trapdoors, and he very reluctantly replaced them, but it wasn't like he didn't have spares...
In the mid-seventies, they located a couple of bales of uniforms from the SAW units, along with horse tack, and they put the word out that if anyone wanted any of it, to come get it, but no one did, so it was all burned.
I'd imagine it was that way, everywhere, if you happened to 'know a guy'.
Scouts Out!