WWII 1944 105mm M14 Shell Casing

While at an estate auction today I picked up this WWII spent shell casing. It appears to be in pretty good shape with original primer and uncleaned. The markings on the bottom are 105mm M14 and below that has ECBC-900, and on the opposite side of the primer has 1944 and what looks like a symbol but I can see it. The primer has 1945, EOP-1-530 and M1B1A2 markings, I can't really read and don't want to clean anything.
Has a later ink stamping that looks like Amm. Lot (something?) then Shell M1 _____? M2, M2A1 & M4.
Called my brother and he said to buy it with a $20 limit and ended up winning it for $14 and at 5lbs. 11ozs. is half way there in scrap value alone. I also picked him up some military pins for $4 and 18 unused Whitman and Littleton coin folders for $6. I didn't stick around for military uniforms due to the heat. I won about 300 45's for $6 in platter-pak and tote-45 cases including a Voice-o-graph I can't wait to play because the hand written name is the Melloettes, so possibly a doowop girl group demo cut, and 36 Topps embossed All-Star cards in NM condition including Mickey Mantle for $32
I may post a few of the other goods in the morning but too tired tonight and everything is looking like junk when I get overtired, but was great earlier.