sorry, the pix aren't really any improvement - are you using a camera or phone? If you are serious about posting pictures on the GMB for the purposes of identification, then the images need to be of good quality. Without looking, I trust that your comments about the period of use for this mark are correct, but just because this backstamp started life at the beginning of the art deco period doesen't automatically make the decoration on the glass an art deco style - and certainly not in this instance. Look at books showing art deco style and fashion and you will see the difference. As you will have seen from searching the Stuart patterns in the link, this factory produced a myriad of styles taken from the last couple of centuries, and from memory I don't recall seeing any which I'd have said were out and out art deco - most appear to be a sort pastiche of classical abstract or floral type of decoration. Am sure that you're aware that some Stuart pieces carry, additionally, the Rd. No., and this can help with identification - although assume yours doesn't. This is all just part of a learning curve, and adds to your knowledge and enjoyment of glass. Do look at art deco styles, which is not time wasted.