The earlier bearings are listed as E14 or E15, an old designation. One of my machines has that earlier spindle, but I have had no need to take it apart so I don't have the spindle and housing measurements.

There are E14 magneto bearings currently for sale and they list the size as 14 x 35 x 8mm.

http://simplybearings.co.uk/shop/p42...duct_info.html

The same company sells E15 bearings: 15 x 35 x 8mm.

Dennis