Not a Seal, Bicycle Valve Dust Caps?

Not a Seal, Bicycle Valve Dust Caps, Image & Found by Adrian G Wright.
Found in Cambridgeshire.

Dust caps for bicycle tyre valves circa World War 1 - easily mistaken for lead but see below.

From David Lindsey, "I think they're a zinc alloy - quite soft."

Now thought to be more likely from military medicines.
GERMAN WWII WEHRMACHT MEDIC OINTMENT TUBE FROM MEDIC BOX LEUKICHTAN War Relic - ebay.?