The books I mentioned were not of any great help, however I have scanned the relevant paragraph [OCR] about H&S from Dr Andrews famous work Australasian Tokens & Coins publ. 1921
Heaton and Sons, the well-known firm, engaged in the production of the British bronze issue with many other Imperial and Colonial pieces, were responsible for some of the best designed and executed Australasian Tokens. Their Mint mark, a minute H&S, only appears twice in the whole series. In both cases it is to be found beneath the shield of Britannia. It is on one variety of each issuer only, viz., the Annand, Smith & Co. penny with twelve leaves on the olive branch (No. 18), and Iredale & Co. (No. 291). The figure of Britannia on the second variety of Annand, Smith & Cp. is so similar that there can be no doubt of a common origin. Then, reverting to the Iredale series, the obverses of the eight varieties are so uniform that they may unhesitatingly be ascribed to the same press, and thus enable us to identify the source of the design of the reverses. Though, as mentioned above, No. 291 has Britannia on the reverse, the other seven Iredale pieces have what is generally described as a “ standing figure of Justice, blindfolded, with scales borne by the right hand, while the left rests on the upturned point of a cornucopia, with sea and a ship in the background.’ ’ This reverse does not occur on any piece bearing a medallist’s name, nor with any obverse known to belong to another maker. Therefore, all issues having this reverse are now ascribed to this firm, an opinion strongly supported by a careful examination of the workmanship and general characteristics of the pieces. It appears on the issues of sixteen firms or individuals, viz. .—Battle and Weight, James Campbell, Smith, Peate & Co., and Weight and Johnson, of New South Wales; Moubray, Lush & Co., R. Parker, W. Bateman (junr.), and W. Jamieson & Co., of Victoria; R. A. Mather, of Hobart; John Martin, Martin and Sach, and Alfred Taylor, of South Australia; T. H..Jones, of Queensland; H. Ashton (pence, 1862-3), J. W. Merrington, and D. Anderson, of New Zealand.
And from eBay an image of the Iredale token, this doesn't appear to have the S doubled this time but unable to be sure.