I've also wondered exactly what they hold - I've probably found 20+ in varying sizes at this dump. The ones I usually find are marked in the same way - a single number on the base, which I assume is a mold number. I'd agree that they're probably late 20s to the late 30s.I noticed one of these in your recent finds. I have found a few of them, the one in the photos has no marks besides a 5 on the base. I suspect 1930s, maybe 1920s but that's a guess. Any idea of what they held or any better idea on the date? Thanks
My best guess is something like an olive, but I'm truly not sure. I'll be turning some of them into Halloween decorations this year.