Please help to identify hallmarks and date

hi, i have 1 silver watch chain but doesn’t have city mark, is that normal?

i only can find a standard lion mark and date letter at T-bar, its “u” i think?

i am really not sure how to identify the date and where it’s assayed.

i saw many of the silver chains without city mark and makers mark, even not a date letter, where only lion marks, are they worth to buy?

please see the photos.

many thanks
a4.jpg
a2.jpg
a1.jpg

no city mark normally Means London.
Its normal that the chain have only lion.

I would expect to see the maker’s mark and town mark on the other side of the T-bar but assume it has been worn off. “u” for London would be 1915 and for Birmingham 1919. Other assay offices (Chester or Sheffield) are less likely. The difference between the two punches would be the bottom rim which has, unfortunately, been worn or polished away.