In 1881 Thomas M. McLean was recorded as a publisher, living at 61 Belsize Park and married to Dinah (b. ca 1832) with his daughter Adah L. (b. ca 1861); Thomas H. Mclean (b. ca 1861) also a publisher; and Malcolm (b. ca 1867), Arnold (b. ca 1863) and Claude (b. ca 1869).
Thomas McLean, printseller and publisher, was at 26 Haymarket, in 1861; it is not clear if this is the same firm as Thomas McLean and Co. who are recorded as photographers at 7 Haymarket, London, from 1867-1869. T. McLean was definitely recorded as a printseller and print publisher at 7 Haymarket in 1872. McLean bought and sold Whistler's etchings over a long period, particularly in the 1880s.
The artist Telemaco Signorini obtained a ticket from T. McLean to attend JW's exhibition at Dowdeswell's, 'Notes' - 'Harmonies' - 'Nocturnes', where he met JW on about 30 May 1884 (he also visited him in his studio on 18 June 1884 and saw the portrait of Sarasate).
UK census 1881, from http://www.familysearch.org (accessed 2004); Kelly's London Post Office Directory, 1861, 1867-1869; Post Office Directory of Stationers, London, 1872; Mayfair ... Directory, London, 1886-1887, 1887-1888; Nicholls, Paul, 'Signorini, la Gran Bretagna e il collezionismo d'Oltremanica' in Telemaco Signorini una retrospettiva, Palazzo Pitti, Florence, 1997, pp. 263-64.