Late 50s Lord Elgin Crestwood
I ended up getting a really nice example of the Lord Elgin Crestwood. My guess is that since the dial has the Durabalance symbol, and the movement is the 23 jewel, 730, the watch dates at the earliest, 1958, and probably at the latest, 1960.
The case is 14K white gold and the dial has actual diamonds for markers, at least according to the referenced ad. The case is 7502C.