Sorry I didn't get back to you, the shape is quite common across the glass world, Bohemia, America & the UK it's just the finish and pontil mark that rules out the UK for me, most UK pieces have a polished pontil mark, remember this is not a set in stone and I may be barking up the wrong tree, when I started collecting I thought all this type of glassware came from the Stourbridge region. As for books there are a few, 'Victorian Decorative Glass' by Gulliver and Charles Hajdamach's 'British Glass 1800-1914 are probably the best. here's one of my unknowns...