Johnson, J. & M (1822-27)
Johnson, J. & M., Clipstone St, Fitzroy Sq., London, cm and u (1822–27). In 1822 at 23 Clipstone St but from 1826–27 the number was 22. [D]
The original entry from Dictionary of English Furniture Makers, 1660-1840 can be found at British History Online.