I thought I had purchased a normal 88mm HE shell at auction in the US. The first thing I noticed about the box was the light weight. When tried to fit it with a standard AZ 23/28 ground impact fuse, I noticed the mouth was too wide for that fuse, and the thread was too fine. What do I have here, and what fuse should this use? Am I missing an adapter ring of some kind? I have had my hands on many 88mm HE shells, but I have never seen this type before. Thank you for your help.