These items were found in Camp Logan, a WWI camp in Houston, TX. When I first found these things I thought they were some sort of tire valve, now I'm not so sure. I've been trying to find out if perhaps they were a previous version of the fuze for the pineapple grenade since they were found in the area where some MKII grenade tops were found. I haven't been able to find what the MKI grenade tops looked like.
Just a word of caution ? Even considering their age (?Especially? might be a better choice!) should you come across one unexpended, those things are going to be extremely unstable. Just wishing you care working around old ordnance areas!!