Dating wheeler and wilson sewing machines
It’s only 3.5mm thick at the edges, see photo above in the summary section.
I have so far not found a modern substitute for this bobbin, so if you know of one, do tell!
See my post on vibrating shuttle machines for more details.
Jones Spool is a rotary machine after Wheeler & Wilson D9, full size only.
The bobbins for Jones CS machines are the same as those used for Singer VS machine, i.e., the “bullet” shuttle.