Maskelyne's perspective would be of interest.
20 years after Longitude... rewriting “villainous” Maskelyne @beckyfh
Having the Arnolds over for tea would undoubtedly make for sprightly conversation:
Name help for 20th c. clockmakers
I inherited and alternately wear three pocket watches, one that my father acquired while in the USNavy in WWII and subsequently used every day of his working life, another, made in 1908, that had belonged to his uncle who had been a chauffeur motoring about in a Pierce-Arrow, and a...
A wonderful acquisition!
Coster's first (http://www.antique-horology.org/Invention/Images/AntHor-par1-Coster_N01.jpg) set the standard with numbered minutes.
Mightn't emphasizing the vastly-improved accuracy from about 15 minutes to 15 seconds per day have proved irresistible?
Silver leaf would tarnish over time (unless sealed with a clear varnish that would dull it.) I would guess that white gold (that is around 50% pure gold) is far more likely to have been used. Palladium leaf might be preferable now, but palladium had not been discovered until after the clock was...
You should visit the Seiko Museum website: Seiko History | THE SEIKO MUSEUM
Information on Seiko Clocks | THE SEIKO MUSEUM
I had emailed them concerning the vintage of the first clock above, and they promptly sent an image of it from their 1961 catalogue.
They may prove helpful...
I had always thought the Bayard Stentor alarm clock that appeared in the mid-1930s a great example of art deco (streamline moderne) design but, before acquiring one, assumed it to be quite a bit smaller than its 150 mm+ (6") height:
It dwarfs my Waterbury Wasp, Spider, Conductor, Hornet...
Any #5 clock key should do, but there are Chelsea keys and reproduction Chelsea keys available from your auction site.
The latter part of this manual may be of interest to you: http://www.90thidpg.us/Reference/Manuals/TM 9-1575.pdf
If you want to date your clock, refer to the serial #...