Seeking OLD HRO Watermaker Manual or Wiring Schematic

[Projectboats]

Hi, I'm piecing together a watermaker from a crate of vintage parts. One intriguing piece is an unused HRO controller of 1970's vintage. I'm told it is one of the original electronic controllers from their "Standard" series. Back when standard communications owned it. I realize this should probably be in a museum but it has some features I would like to utilize, such as a TDS meter,big relay for the pump, etc. Sea Recovery, the current ownership was of no help. Their techs probably weren't even born. Does anyone out there have an old HRO manual or wiring schematic?
thanks, duncan
M/V Turning Point
seattle

[wingover]

Does it looks like that? if so I also have the drawings.

[Projectboats]

Thanks for your help. Unfortunately I think mine is even older than that one!
It's blue and labeled HRO and Standard Communications.

Duncan