AZ23/28 Fuze

This is an impact nose fuse for the infamous German '88' of WWII (and will also fit a 105mm). Used by army, navy and airforce in anti-aircraft (Flak), field guns and tanks.
Still looking for a better typeface to use on the stamped lettering ('though it did vary between manufacturers), which is way too deep and heavy but about the best I could do within the limits of my FDM printer.
I had some good sources to work from, so this should screw into your old projectile if you have one. (If you don't have one, try printing one of my matching Flak projectiles, https://www.thingiverse.com/thing:5173935)