I don't think I've seen one of these in a selenium/uranium combo before
I have two pieces in this style, both the 3-pronged affairs in two different sizes. Sadly, the large one later became a 2-pronged affair... but it did have stress marks in the glass so I wasn't surprised when it fell apart.
But I am quite staggered to see that Davidson was involved with these. Just playing Devil's Advocate for a while:
Could the label have been transferred across from another piece of glass?Could Davidson have imported these, or perhaps another English company produced for Davidson who then labelled them? Nazeing perhaps?
However, Chris' site does state (although probably unrelated):
In 1966 the first adverts for Blown Lead Crystal glassware appear. In an age of mass production, Davidson started to advertise the fact that their products were hand finished, stressing that hand moulding and freehand styling of glassware was a reason to buy Davidson glass.
Just thinking out aloud, as it seems so unlike the type of glass that it is known for. Perhaps a last throw of the dice? The company did free-form a few items of pressed glass, but these items involve techniques quite alien to its normal production items.
Like everyone else, I would love to find out their origins!