I found this WWII era 90mm blank shell casing about 20 years ago, partially buried in the sand in an eastern part of the Mojave Desert.  I suspect that it was left behind after a military training exercise.  It is well preserved and has great patina.  No cleaning or restoration was ever done to it other than washing it off with a water hose.  Even the black stenciling on the side is still clear and legible.  The primer tube is intact.  There is one small dent on the lip of the case that can be seen in the photos.

The casing is made of solid brass, stands 7 1/4" tall, and weighs about 6 1/2 pounds.  The base diameter is 5 1/8", and the top rim measures 4 1/2" across.

Stenciling reads:  "CTG 90MM BLANK / M394 FOR GUNS M36, M41 & M54 / CHG WT 2.20 LB / LOT IOP - 4-19".    The year 1944 is stamped on the bottom of the shell.

I think it would be difficult to find a nicer, more well preserved casing than this one.   Can ship via USPS for $13 to $18, depending upon location.