For a detailed discussion on this rare group of wares see R.J. Charleston and J.V.G. Mallet, 'A Problematical Group of Eighteenth-century Porcelains. The 'A'-Marked Group - Italian or British?', E.C.C. Transactions, Vol. 8, Pt. 1, 1971, pp. 80-119 who concluded that the 'A'-marked wares have their origins in Great Britain, suggesting that both Nicholas Crisp's factory at Vauxhall and Alexander Lind of Gorgie, Edinburgh, merit further investigation and ibid, p. 89 where the present teapot is mentioned. See also Nancy Valpy, 'A-Marked Porcelain: 'A' for Argyll?', E.C.C. Transactions, Vol. 13, Pt. 1, 1987, pp. 96-107, where she strongly favours Lind of Gorgie, patronised by the 3rd Duke of Argyll, as the possible manufacturer of this group. On the evidence of paste and glaze and the recorded shards from the factory site, a Vauxhall attribution seems most unlikely