Guys - I understand that when Keystone bought Howard, they revived their patented non-pull-out design for the bow on a watch case. There is an ad that refers to this as "standard" on the company's RR-grade, 16s factory cased and timed watches...circa 1912. I have questions I hope the experts can answer.

1 - If these cases are identified - how? (Could it be that when marked "Extra" they mean the bow rather than thicker rolled gold?)

2 - if not, can one determine if they are non-pull-out by some means without disassembling the case?

3 - Was this patented bow used on brands other than Howard? (For instance, Illinois advertised bows that "absolutely will not pull out" in their information on factory cased 16s Bunn Specials. Were they a different design or the Keystone type? How about Hamilton, Waltham, Elgin, Hampden, etc?)

4 - The patent dates to 1891, but back then very few watches were factory cased, and many were 18s as well. Does anyone have an example of the non-pull-out case on these older watches? If so please refer to question number 1 and feel free to educate me!

5 - When were N-P-O cases introduced on Howard watches and how long were they offered?

THANKS in advance for any help on this!