Hi Tackle-holic.
Thanks for the reply.
Removed all 3 Shims now and the spool, when turning without spool still 'sticking' at bottom when rotor turns.
That sounds like the main shaft might be bent.
Remove side plate.
Unscrew the 2 screws that hold the main shaft to the oscillation block and pull the man shaft out (no need to remove rotor)
Roll the shaft on a flat surface (with the brass spool bushing/seat hanging over the edge)
If it slightly bent you will feel it