BSA. Spare parts list for 500 c.c. S.V., Solo motor cycle, Model WD/M 20, Contract no. S 2603, Frame and engine numbers W.M.20-96818 to W.M.20-104818 Ariel motors LTD. Maintenance manual and intruction book, Ariel motor cycal, solo350 c.c. O.H.V., model W/NG. BSA. Spare parts list for 500 c.c. S.V., Solo motor cycle, Model WD/M 20, Contract no. S 2603, Frame and engine numbers W.M.20-96818 to W.M.20-104817 BSA. Spare parts list for 500 c.c. S.V., Solo motor cycle, Model WD/M 20, Contract no. S 5209, Frame and engine numbers W.M.20-104818 to W.M.20-116817 BSA. Spare parts list for 500 c.c. S.V., Solo motor cycle, Model WD/M 20, Contract no. C 11101, Frame and engine numbers W.M.20-53413 to W.M.20-61412 … BSA. Maintenance manual and instruction book for motor cycle (solo) 500 c.c. S.V., Model M 20