Andrew Nethercott Antiques has dated this piece to the 1910s.
Large strong twisted curb chain links, matching hallmarks throughout, assay mark Birmingham 1913
makers mark F.W.C for Frank William Cole / F W Cole Gold & silver chain maker, Vyse Street, Birmingham

Sliding ring type T bar mount with large ring retainers at chain ends.
In excellent condition with very little wear, good, sound, strong and ready to wear.
Total working length of chain 17" or 432mm, weight 75 grams
Andrew Nethercott Antiques has dated this piece to the 1910s.
Works of art, collectables, scientific and decorative antiques from the 17th - 20th century
You can view the stock and full dealer information on the Andrew Nethercott Antiques Profile Page