I have a watch with makers mark George Stockwell and the london import mark circle with a U in it. Post 1907. To go further in researching the item there is a 6 digit number which i assume is the makers reference. Are there records kept to reveal the details of this reference or for whom the watch was made even? Thanks.
Usually the outer case will be made by a silver smith and the watch works are made by a clock smith, you can sometimes find signature or names on the works of the clock smith.
If you can find a date the watch was made and who the silversmith was working for at that time you can contact the company (if they still exist or were purchased or amalgamated into another company)
They will have kept records.
Its hard work and in my opinion not really worth pursuing unless the watch is of a very high quality.
You are correct in stating this is an import mark
Its not a “U” its an inverted Omega (London Assay mark)