I think this is a "twisted variation" of the Strathearn Aurora design and the twisting has elongated many of the bubbles.
The coloured chips used in yours are much the same as in my D29 Jumbo version, which is the Green one shown in Richard More's site (unless he has updated it with another example). Mine is 4 x 3.5 inch (102 x 90 mm) but the other example is clearly more spherical, as is yours.
However, depending on the actual size and the number of rows of bubbles, it could be based on the P28 Large. Richard points out that both the Jumbo and the Large were made with a Grey background and I think that is what yours has.
Could you please give height and diameter and if possible the number of bubbles rising up the twisted ridges. I cannot easily estimate the bubble count from your photos but it appears to be greater than 10. My D29 definitely has 13 rows of bubbles.