In the listing from 1939 they are shown as R.S.Brookman Ltd so there was a slight name change. From Co. to Ltd
R.S.Brookman Ltd are known for their dovetailer, which on the ones I have seen don't have an RSB logo but a Brookman logo.
[http://www.gregory-woodworking.co.uk...pg&w=450&h=299http://media.scosarg.com/media/catal...a/mabm15dt.jpghttp://greenfieldsfinefurniture.com/...s/brookman.jpg
- A 1938 issue of The Architect & Building News has a news snippet:
R. S. BROOKMAN LTD.—This firm are showing for the first time at the Building Exhibition. Their principal machines will be a versatile dovetailer, equally at home on mineral water boxes and high-grade cabinet work, and a mortiser, adaptable for single pieces or for fast repetitive work.- Listed in a 1992 issue of Wood Technology as a maker of mortisers and dovetailers.