STER Earrings with illegible (to me) Stamps Marks

[Ldyma]

I have just added a beautiful Set of earrings to my collection
It doesnt look like they are American as the STER is ffollowed on one piece by what looks
like four digits. Year maybe? Then possibly a head?
On the second piece STER is followed by what looks like a crest or other makers mark and the same
"head" like symbol as the other
Can anyone help ID these strange markings?

[dognose]

Hi,

Welcome to the Forum.

I think we will need large close-ups of the marks if anyone is to help.

Trev.