Hi Tony
It's not really the instruction book you need. It's the wall bracket itself. This would have been supplied new and is nothing than a square ish metal wall plate that has hooks on it. You simply fix the plate to the wall and the Lab2000 slides on from the right side and locates in place.
There was also an optional corner bracket that allowed the Lab2000 to sit across a right angle. You mount the supplied square plate onto the corner bracket and the fit the Lab2000 as normal.
Both brackets are no longer made but I'm sure you will be able to pick up one or both second hand if you need them.
Opman