Vintage Simmons Drums (UK) Users Group

Does anybody know where to find one of the SDX workstations touchpads 
and a cursor-ball setup from the early 90's..I worked with a 
band "Valentine"..and we had the no- onboard memory prototype...then 
had one with memory..They're hard to find..Our rep back then only had 
sent prototypes to Bill Bruford and Alex Van Halen at the tim...kinda 
looks like the old PET computers in black .. from the early 80's