The short case is for howitzers -
Your case is not over stamped, these were all marked this way in 1939 ,
F.A.E.D.B. is the Frankford Arsenal Engineering Development Board, this case continues the subcal mark from the first cases.(In 1940 some were marked M4 AUTO GUN instead of Subcal, later 1940 cases are marked MKlll and there after) The earliest I have seen are dated 1911, but they might go back to 1908 ? These Frankford Arsenal cases with script seem to have been made up until 1917. All the 1918 cases I have seen are made by P.E.&M.Co. I have not seen an interwar dated case yet. The 1918 P.E.&.M.Co. were still in use in WW2, I have one loaded for the Airacobra and have them primed in 1941 for subcal use. There are two kinds of these long 1.7 Pdr. projectiles. The Model 1908 1 Pdr. (Maximum Capacity) was also standard with these and stayed in service with several variations into WW2 as the M94, these were used by the Coastal Artillery. I haven't yet found official information regarding the introduction of these long 1.7 Pdrs, or when they were discontinued and the same for the introduction of the 37x145 case. Previous to this the Navy length 37x136 case was in service and likely the two overlapped for some time.
I notice I haven't posted my U.S. Army Subcal assortment. Will get to it.
I will start with the first two kinds. The first is the Navy 1 pdr. adopted by the Army for Subcal use. It was superseded around 1906 by the new and improved Maximum Capacity 1 Pdr.
--Am still searching for one of those hard to find short Subcal cases :tinysmile_cry_t4: