This is a really wonderful pocket watch! The watch itself is an American Waltham Watch Company "Marquis". It's 16 size, Stem wind & pendant set, has 15 jewels and dates to about 1918 [serial number 21769934]. A nice watch, granted, but not overly unusual.
The case, though, is something else! This watch was actually made specifically for the English Export market and it has been housed in a really stunning triple-hinged gold-filled "demi-hunter" case that allows you to tell the time even when the front cover is closed. Not only is the a little window in the front cover and numbers along the edge of the case, the hour hand actually has two spade pointers to indicate the hour whether the cover is open or closed. The inside of the back cover is marked "MOON" and "A.L.D. DENNISON WATCH CASE Co., Ltd." The inside of the dust cover is further marked "ENGLISH MAKE" and "GUARANTEED TO BE MADE OF TWO PLATES OF 10 CT GOLD WITH PLATE OF COMPOSITION BETWEEN AND TO WEAR 20 YEARS." The case also has some of the best engraving I have ever seen on the back of the case, with what looks like the letters "HB" in ornate script.