It seems likely that only one issue of the Sheet Almanac was published by Tegg's. According to an advertisement in the Literary News, 13 January 1838, the almanac contained 'much useful information, and a corrected List of all the Mails to and from all the principal places in New South Wales'.
Source: Ferguson, John Alexander and National Library of Australia. Bibliography of Australia. Vol. 2. 1831-1838. National Library of Australia, Canberra, 1975. Entry no. 2644)