J.B. Bateman was another printer used by the Brethren from at least the early 1840s to the late 1860s (from tracts on this site).
A few things are said of him in this paper on The Missionary Reporter.
He seems to have began in the 1830s from premises at 109 Fetter Lane, where in City Directories he was described as a "Printer, bookseller, & stationer". Around 1842 he was at, 1 Eilm Place, Fetter Lane, then from 1844 to the late 50s, 1 Ivy Lane. After this, from around 1860, 22 Paternoster Row (an address later used by Stow Hill Bible and Tract Depot). Then from sometime in the late 1870s, 26 Paternoster square.
I don't know if he ever had a connection with the meetings, or why he was used by them as a printer. Given his involvement in Christian printing endeavors, particularly those with William Yapp, one assumes he was a believer at least. Also one of his sons was given a very Biblical name, Silas!