Hey, I just got ahold of what appears to be a spherical case shell. The diameter is just slightly larger that 3 7/8". The shell is perfectly round with no markings or indentations. There is the usual mold separation line around the circumference. The fuse hole is plugged with a simple brass plug, two holes for the wrench, but no hole in the center for fuse purposes. The plug is stamped with the word "GILL" and it has a number 8 below that. It measures 13/16". I take it to be an 8 pounder but can't think of a US or CS bore that size. I do not have a photo ready yet, but wonder what you may think it is. I don't know if it's inert or not, just that it was found in an abandoned garage about ten years ago and then kicked around the guys house until today.