Thank you both. I like the bright finish more than the frosted in this pattern, especially in the large size.
Paul, I hadn't noticed the price difference between this and the butterfly and panel vase until you mentioned it. It may well have been down to success rate as the Butterfly and Panel vase has quite a complex mould where the foot follows the shape of the butterflies' wings. It also looks a little larger than the bird vase and from my examples it seems to have often had more cold work done. All five Butterfly and Panel vases I've owned have ground and polished rims plus some areas of wheel polishing on the vertical panels (presumably to polish out moulding imperfections/ bits of stray frosting, etc.) whereas Bird and Panel vases just tend to be fire polished, and, if frosted, are frosted all over with no areas masked off or selectively polished. That said, I have just spotted a Butterfly and Panel on ebay which just seems t have a heat finished rim and no signs of frosting or wheel polishing...
Jade and Opalique were more expensive to produce (I recall Bernard saying that Jade was Jobling's most expensive to make) and seem to have commanded a premium on all patterns except the large Lambton table/ lighting bowls.
Anne, yes the Reg. No. is in an odd place. Both the 10 inch and 8 inch vases have the mark in the same place on the upper surface. However, the early examples of the 10 inch are marked "Regn. Applied For" in the more conventional location across the underside of the base.
Steven