Not sure, but I think these might be 'commutator lathes' for making electric motors.
EDIT;……Keith Blackman motors….notable makers of eletric motors listed in various locations including Colchester and Tottenham………Suppliers of motors and fans for boats….apparent supplier of 30HP motors for RN 'X craft' submarines during WWII…….
………..Maidenhead is on th Thames and has boat yards etc……
Edited By Bob Stevenson on 05/06/2016 22:19:37