Greetings all. I haven't pestered you for a while, so I thought it was about time!
I recently won a Keystone Howard and had a couple of questions. I'm really just trying to figure out what it is.
Serial number is 1203089. 17 jewels. It says Pat'd 12 instead of Pat'd 18 which I've seen on a close number online (though to be honest, I'm not sure the significance of either). Am I correct that it is a Series 7? 1915 ish? It's my first Howard and I just looking for anything you guys know.
Thanks and here are a few pics.

It's missing the second hand and the other two are pretty rough. It appears to have an old plastic crystal on it which I'm sure didn't help anything.

Crescent case with just a plain back. Nothing engraved.

And the E. Howard engraving inside.
Any info you want to throw my way, I greatly appreciate.
Thanks and a good weekend to you all!

Edward - Yes. Your watch is classified as a Series 7, featuring 17 jewels, and adjusted to temperature, isochronism, and three positions. The updated patent marking indicates improvements in the setting mechanism. Attached images are from a c.1909 Howard Watches catalog describing the Series 7. (Notice your watch is not fitted with the stop-work mechanism)

Patent Documentation:
US1013896
US1029116

It is a 12 sz 17 Jewel Series 7 made around 1915. It is missing a regulator spring.

regards,
bb

Thank you gentlemen!
As usual this site is the best.

For Buster and others, does E Howard have a detent stem much like some South Bend, the Elgin 57X series along with some early Hamilton grades?

The 12s Keystone-Howard's sure do have a detent stem Claude. So if anyone has an uncased one they will have to find the stem as well

What I thought, picked up a 12s 19s missing either the stem and crown or just the crown but I tend to think it is both crown and stem. I noticed the small screw to set the detent so one lesson learned on Howards.

Just about those regulator whip springs Edward, be aware that there is a difference between 12 size Howard whip springs not all will interchange.

This seems to be a weak spot with these models, as a great deal of them you will come across have broken whip springs in my experience. Yours might have been pilfered for another watch