Looks very similar to the Caithness weights, first issued in 1972 (both Single and Double Harlequins). They come with either 6 or 8 peripheral bubbles ... but usually contain a signature cane - either PH (Peter Holmes for 1972-1975) or CG (1976). This cane might be distorted, however, and difficult to identify: can't see it on your images, but you may want to have a closer look for it.