who are WOSP stockists very kindly supplied me with a pinion fitting kit, which included the missing washer, FOC. Quite a contrast to PowerLite who would only supply a new motor complete. CCW appear to stock all the spares for the motor you might need. So it is now fixed.
![Very Happy :D](./images/smilies/icon_biggrin.gif)
Here's a pic of the new washer on the shaft to show scale:-
![Image](https://i.ibb.co/Q92JvKz/20200620-131946.jpg)
And a pic of the old pinion and the new fitting kit which shows the splined washer.
![Image](https://i.ibb.co/zrcdbZq/20200620-131811.jpg)