Don't be offended but it's possibly as far from Stevens and Williams as it's possible to get and still be glass... With that cased colour and texture it looks very Empoli to me.
I'm not at all offended, I originaly told him 1950s continental. I then came up with my S&W theory as I have a small S&W with the same caseing, colour & shape & a snap pontil. The glass is totaly diffrent as the S&W is like bubble glass.
This is a very odd piece to me & the photo isnt to good. I think its one of those that you'd need to have in your hand.
It has a snap/rough pontil btw & is 'tripple' cased, it doest to me look older than the 'retro' period.