Hello Jeoldrid
Assuming that Searle Bros. produced between 1,000 and 4,000 negatives per year, I think your photo was probably created in 1885 or perhaps 1884. The number 45365 is about 1,800 below 47170, which appears to have been pencilled on the back of a carte de visite dated May 1886 (a portrait of 21-year-old Harriet Louisa Florence Kennedy, currently available through
eBay).
There are many useful biographical details but unfortunately several inaccuracies in the old
photoLondon database (recently resurrected in a modified format by the Museum of London) which is no longer being updated.
For the record, the studio is listed in Kelly's directories from 1882 until 1931 at 191 Brompton Road (Knightsbridge, pictured
here in 1903). Although called Searle Brothers, it was operated by the Stuart family. Its high serial numbers had presumably commenced in another studio. The photographer William John Stuart (b. Sidbury DEV 1839; m. Hannah Jones at St Mary's Marylebone MDX 1864 ["Foby"]; d. Warlingham SRY 1915) had premises in Surrey and at 47 Brompton Road in 1868 when he announced that he was changing his surname by deed poll from Toby to Stuart (The Standard, 8 August 1868, page 1, column 2). His eldest daughters had already been christened with Stuart as a middle name (Edith in 1865 and Lilian in 1867). The business was carried on in Brompton Road and elsewhere by William's sons, Charles Stuart (1873-1916) and Archie Stuart (1877-1947). Archie's continuation after the dissolution of that partnership was confirmed by a notice in the London Gazette on 5 August 1921 (pages 6233-4).
I'd be interested to know why William became a Stuart and why he chose the name Searle for 191 Brompton Road. The studio at number 47 had been run by (Samuel) Robert Stuart (c.1826-1903) for ten years or so from about 1855 (
photoLondon). Its address was 16 Middle Queen's Buildings in the 1850s and 9 Queen's Buildings in the early 1860s, before the road was renumbered in 1864. Samuel / Robert subsequently abandoned photography to serve as a licensed victualler, apparently at the Beehive in Islington MDX (from April to September 1868; the licence was then transferred to Mrs Jessie Stuart, who relinquished it in 1870), at the Bald Faced Stag in Finchley MDX (1869-72 ["Stewart"]) and at the Brockley Jack in Lewisham KEN (1873-77). He spent his retirement in Bexley KEN, where he died at the age of 76. Born at Harwich in the north of Essex, he seems unlikely to have been closely related to William Toby / Stuart but may have employed him or merely sold him the studio.
David