Sorry... I thought I had included this one too. You can barely see the number stamp.. but it's definitely 2486... and you can see that there are a couple of black specs. Thanks again!!

Thanks to The Logician LLC and rhizo_1 for the answers. I found these on a window sill (outside) while staying at a friend's house in Galway, Ireland. It has been a warm spring with little rain. They are quite tiny, a few mm in length, and move very quickly. They did not move indoors.

Hello...I'm struggling to find a couple dozen shelf brackets as shown for two vintage metal bookcases. Can anyone help me identify these and ideally point me to where I can purchase more? Thanks to all in advance!

If you, or someone you know, has computer skills this may be of help. https://quiltingjetgirl.com/2015/09/19/reverse-image-search-tech-talk/