'Famas' branded equipment was manufactured by Radio (1936) Ltd, they were distributed by Farmers Trading Co. Ltd. Currently there is 1 documented model.

Press 23 December 1940Press 7 December 1940

The Famas brand appears to have been an in-house one for Farmers  It appears in advertising during, and just after, WWII.  It was not just used on radios and appears to have been a house brand used on products made specifically for them - for example, the brand was seen on boots as well:

Press 12 June 1942

Where the model code is not clearly stated it can be found (in most cases) as the letters at the start of the serial number.  For example, RB10574 would be a model RB.

1 Documented Famas Model
1940 Famas model EB 5 + magic eye on some sets  Dual Wave