Featured Converter strap pocket watch to wrist watch

Another interesting item from my latest bag of mischief (or scrap as my OH calls it).
My research tells me this is likely a converter to wear a small pocket watch as a wristwatch but I can’t find many examples to date it. Some seem to suggest 1910 ish.
It’s has significant plate loss and the leather strap has been well worn but I thought it was an unusual item.
Any thoughts please?
Thanks for looking

 

Agree with the 1910\1920s era.
Does it have a patent number on the system?

 

It’s stamped PATENT but I can’t see a number after it. I’ll look later when the kids are in bed and in better light. It does have some odd marks scratched by hand into the back Q 1.3.1 and N 1.9 (the 1.9 is indistinct but suspect they only meant something to the writer)

 

I owned a couple of these that I picked up in Germany. Sold a similar one, but with a rolled gold band for $50 a few days ago.

 

Thanks Barn!.
Interestingly it arrived with a RG band too. I didn’t think much of it but maybe they belong together. I will probably sell them together too as I have no use for it and it’s not my thing.

 

https://www.ebay.de/itm/Friedrich-S...le-Tula-Silber-um-ab-1915-67655-/363152345457

 

Thanks Fid!

 

just in case you see the remnants of a mark somewhere:
http://www.jewelry-and-more.de/deutschland/fr-speidel-pforzheim/

and for indepth research not limited to English, there were many around stamped Amerikaner (for Amerikaner Gold), which simply was a bit a thicker goldplating than normal, but still not worth trying to scratch it off. the core was mostly copper or brass.