Looks kind of small and is crazy expensive! 
hopefully I didn't pay anything for it, it was lying around and old sun workstation

Your also going to have to find a way to mount it. Why not just use a arcade trackball? You can either buy an interface like the optipac or Oscars USB board or you can buy a arcade trackball with mouse interface built in.
I guess mounting it will not be the problem, my main concern is that is it "plugable" to an optipac. I'll order one from ultimarc.
I realise that I didn't give enough details. I just want to use the mecanism, logic board and plug the whole thing to an optiparc.
and finally for the momment, if this solution is viable, it will allow me to save a few bucks, ie better spinner or ....

Eric