The Golly Balloon Badges
There are a number of different variations to this pin: Front view (this one); Front view with pierced arms; Three-quarter front view. And each of those have either a gilt or chrome finish to the badge and some have a manufactures imprint on the back. Plenty of scope for the discerning collector!
This pin is of Golly I and Golly III. It has a gilt finish but can also be found in chrome.
These badges are a little over 28mm in diameter and have either a white enamel background (shown above) or blue.