I ran across this the other day and thought it was interesting...It is a swing out 18 size sterling case with an odd crown..Has anyone seen one before..I hadn't so I thought I would ask you guys..

Top part screws off to wind..

It is a swing out sterling case it a female winding stem..You could also put a male stem in it because the crown does lift up but is odd because it is spring loaded..

A shot of the back..

As you say, it is an interesting case. From the serial number I would say it was very early and probably a "transitional" case when watch co. were going from KWKS watches to Stem-wind watches.

I have seen these with a plain KW type unknurled cap that one removed to wind a transitional movement, yours appears to have had a knurled cap which is greatly worn down due to the soft silver content. I suspect that a lot of these caps were in fact knurled to help one unscrew that cap.

Very nice, I can't quite make out the case maker, looks like "_&_ Co."

As with the main components of a watch, there are probably "case collectors" that would love to have that case !!

regards,
bb

Buster case maker is A.W.Co...

That's not too far off how a modern waterproof dive watch stem works.

I wonder if it was an early effort in the direction of dust proofing.

Is that a patent number above the makers mark?

Paul the Pat'd is Apr 22, 1878 or 79 can't make it out clearly..The odd part is the stem does lift up but does not have a sleeve so it doesn't stay..Rather it is spring loaded and as soon as you let it go the spring pulls it down..Enclosing another picture of the female stem..

An American Watch Co., Waltham model 1877-1879 should fit that American Watch case Co. lever set case with correct set lever slot and feel just as much "at home" as the first 1877-89 AWWCo., Waltham movement did!

Similar to the below Model 79 American watch Co. Cased example that recently passed through my collection