I have a few 3" wico/imperial track balls that are used, working, but if you are like me you will want to get new rollers for them $20 each. the optic boards in there are with more than that.
1 used happ 3" trackball same as above condition, $32.50 (I know strange price but i could not make up my mind between $30 and $35)
more stuff to come.
Real cost shipping to be added to those parts.
Please email me at daveb at drindustries.com