Help identifying silver cigarette case

Ohhh, when I zoom in even more I do see a W there. To me it's kind of faint/hard to see and its only visible in one of the ovals. At first I thought it was just a blenish of sorts.
Interesing! Thanks for the help so far!!
Now, looking at the website link you provided for me, there isn't anything that resembles the other stamp (not the oval, but rectangular shape). Hmmm, but it's safe to say it's from that era still, 30s-60s?

 

Yay! It was too late for me to get terribly far last night, but I was going to ask this morning if we could get a better look at the oval. Glad to see that you beat me to it, INH!!

 

It kind of looks like a sideways tiny 'w' is there.....but what I said about that program.....it can also distort images and that's only at 2.5X mag......

 

Thanks for helping us narrow it down, guys! Awesome!
Is there any way to narrow down the year?
With it being 80% silver, 20% alloy, does that mean it's a sterling silver? I am asking because I want to clean/polish it but don't want to ruin it.
Also, does anyone know what the 17 inside the triangle could mean?

 

Sterling is 92.5 % , only !
at 800.....you can still polish it to a gleam !!!

 

But .800 silver is still a solid silver alloy - not plated, if that was behind your question.

 

Brilliant, you are!

 

No other marks on the case, i need help.

But this has reallly been helpful guys. We're grateful! If anyobe has anything to add - that would be cool. But we've really got a lot of interesting info that we're excited about. Thanks a bunch for your time, guys.