Ross, what a great puzzle! I agree your three items seem to be made by the same hands. While they are similarly decorated in the bodies, the shared characteristics are even more apparent in the bases. The bases have the same shape, the same finish of the spiral stripes, and the same treatment of pontil scars. Even the irridized colouring looks more similar in the pictures of the bases than in the main photos.
I'm confused when Ross says (in Reply #5) "The paperweights have a different type of iridescence as well." Does that mean different from the vase, different from each other, or different from IoW?
There are many reasons a work like this goes unsigned. I'm not thinking of production ware, which may be made by anonymous assistants in any case, but of items clearly intended as decorative arts. Some makers are reluctant to sign, for reasons of modesty or from a wish to acknowledge a shared production effort. I have read that of Michael Harris, although whether true I do not know.
Other reasons items that might normally be signed remain unsigned include error or forgetfulness, theft of unfinished stock, sales in the studio from stock, items deemed to be of second quality, etc.
It would help the detective work, Ross, if you could tell us where and when you acquired them. If bought online, the location of the seller(s) might help. Small items such as these can travel far from their place of creation. The distance is likely to be greater if they shared that journey than if they travelled alone and found you quite independently. Unless there is some reason to believe these items are well-travelled, I am inclined to focus on Australia as the source.
I agree these items are unlikey to be by Colin Heaney. There is a general inclination to attribute anything with this irridized metallic finish to Heaney. His output was so vast and varied it is unsafe to claim something is definitely *not* made by him, without good evidence, but sometimes it gets ridiculous. Items are often falsely attributed to enhance their sales value. I even saw one item recently that was clearly signed by another artist described as "Heaney era"!
I think Ross is saying that there are few unsigned items that can be reliably attributed to Colin Heaney. If so, I agree. Many of the unsigned "Heaneys" offered by vendors turn out to be something else. The only examples I can safely point to are the statue in the photo below (which was likely intended to be part of a larger work) and some of those wonderful flowers he made (in a bunch where some are individually signed and some are not).
Ross's items do not look at all like anything I've seen produced by Martini Glass (Tina Cooper and Mark Galton).
OK, so who made Ross's three related items? Even if the evidence of place and time suggests Australia there are a number of possibilities. Some of them may even have been working with, or for, Colin Heaney, or were by then independent artists who had trained with him. Another suggestion that fits better with the quality of workmanship is a contemporary of Heaney whose early work Ross discovered recently, namely Alan Fox of WA. However, I cannot find any examples of Fox's work with the same swirled decoration nor the fire-polished pontil scar. So the puzzle remains.
Trevor