#1 looks like the metal end of a shotgun shell?
#2 ?
#3 Is the type of key used on older gumball machines
#4 Link from a larger chain?
#4 Looks like the loop from a canvass or leather item
its looks like a post office key or a safety deposit box key the 2nd pic looks like a radiator cap maybe cant really tell with nothin beside it to compare the size with
its looks like a post office key or a safety deposit box key the 2nd pic looks like a radiator cap maybe cant really tell with nothin beside it to compare the size with
If you use the size of the shotgun shell end and the pattern on the background as scale #2 looks about right size for radiator cap. Could be right there.
In your case, a grommet is what would go around a hole in a tarp or canvas where a hold-down was needed. Whatever was being covered would have a corresponding post with a twist head on it.
I agree with wvwildman that the key looks like it's to an old postal box or lock box. Hard to say on the shell. Maybe someone with expertise in ammo can tell us.