Lucas B90 factory exchange service book/manual with specifications for all British motorcycles with Lucas electrical components from 1939 to 1957, the book is 15 pages 8.5 x 11 inch format and in excellent unmarked condition, and looks better in the hand than the scans below convey. it list all makes and all models from the makers which carried Lucas components, with a separate box for each model with all the parts used - like Control Box, Magneto, Horn, Magdyno, Generator, Stator, Armature, etc. with years used and part number plus a suppression chart - it has all parts numbers and is an absolutely superb cross reference book to see which models and makes used the same components from the 1930;s to the 1950's and covers all models made by the makers as follows from 1939 to 1957 - AJS, AJW, Ariel, Brockhouse, Brough Superior, BSA, Cotton, Douglas, Ehrlich, Royal Enfield, Excelsior, James, Sarolea, Matchless, Montgomery, New Imperial, Norton, OK Supreme, Panther, Scott, Sunbeam, Triumph, Vincent HRD, Veleocette and Zenith.