When the auction house dont no about this Hallmark/makers mark - then who Does.?

[tictoc]

Hi all.
A month of emailing auction houses and showing independent antiques shops and searching online and no one has a clue.
If all else fails the forums should no.

Any help with this makers mark please...?
the other side of the clips has 585....

Who is this makers mark.???????????????



Thank you all inadvance.