You could make the spools out of dowels and plate.
The plates could be pvc or styrene sheet, or perspex.
Brass dowel and sheet would work also.
Just use the big round circular servo "arm" and screw it to the outside of your
spool using a few self tapping screws. Then it will mount to your continuous rotation servo.
I have used G scale railroad wheels as spool sides before.
I did, however, do a bit of extra shaping on the lathe though.
For the hand winch I used a wood dowel and a styrene plate cut using a compass cutter.
And did a similar spool half for the Patterson upright winch.
