Stew - great glow, but I'd also suggest a fire polished rim from what I can see in your pictures. From what little I know of coloured Victorian material, I get the impression that ground/polished rims are more an indication of Continental origin - and doubt that you could tie down to a maker. Leaf trailing was certainly a common form of decoration on this type of object, and turquoise a not uncommon colour.
Have a feeling that these shapes are called 'shaft and globe', and would humbly suggest a date a little earlier than your 1900 - perhaps more 1870 - 1880.
What makes you suggest Boulton & Mills??