The following from Whites 1873 directory may be of interest:
Mountford James, engineer, millwright and machinist, Bridge street mills
Mountford John, engineer, machinist and tool maker, Brasshouse passage ; h 58 Heath street, Dudley road
Bridge street Mills are in Bridge St, off Broad st, but I am not clear exactly where in the street.
In Kellys 1876
Mountford John, engineer, machinist. &; tool maker (established 1820), 22 Brasshouse passage, Broad street
Mountfbrd James, engineer, 9 Clement street
No home address is given for either in 1876
Neither are listed in 1880.
The attached map shows Brasshouse passage (in red) in 1890. It was narrow, but a fair length.
mike