I had two, first one purchased in 1981. Only three dials, one for pump pressure, vac and water temp.
I had both water tanks replaced with SS ones as they soon perforated due to the strong alkaline chems in those days.
Also the eletronic waste tank cut out, module would play up, so ended up bypassing it.
Great bit of kit in its day though, sengle 3 phase vac with 50 psi pump. Kept me going for the first 17 years in this business.
The owner of Stimvac was an Asian guy by the name Mr. Ali.
Dave.