Hello Pratap.It is of a prewar-early war M20 front wheel with the speedo drive in the brake plate.Its the dust cover that goes on the L/H side.When BSA changed the speedo drive to the left hand side that part was replaced with a fixed item with 2 cutouts to turn the speedo drive.Hope this helps,Sam.

email (option): smarwick@iprimus.com.au

OOPS!... ...I wasn't thinking about the early bike...Ian

email (option): ian@wright52.plus.com

Thanks Ian, Thanks Sam, hightly appreciate your help.

Regards
Pratap

email (option): prataphenry@gmail.com