This set  works out slightly cheaper than buying the parts individually. It consists of the following items which can also be bought individually:
1 set of Heavyweight Webb Girder Fork Spindles
1 set of Heavyweight Webb Fork Spindle Nuts
1 set of Heavyweight Webb Fork Knurled Washers
 
This set will fit Heavyweight Webb forks as fitted to the 1920's Norton CS1 and ES2.