That throw-off would date it, I think, from the 1940s...earlier versions of that drum had the "timepiece" throw off.
The Imperial lugs came out in '36, originally without inserts for the t rods...they were tapped.
Usually, drums with your throw off have the white badge...the white lacquer may have been removed or worn off. Just a hunch.
These drums were made by Conn in Elkhart in the same factory that made the Leedys of that era. Eventually they changed the white badge to say "Elkhart" and soon after that they merged both companies into Leedy Ludwig.
Nice drum!