I believe the triple Weber manifold was made in Australia, any idea who made it? I have one identical to yours with nothing to identify who made it. I am going to try a triple SU (it's a Lynx) in my wagon then might give my triple Webers a go.
There were a few makers of aftermarket intakes in Oz many years ago, Speco, Lynx and Cain were the popular ones.
Mine is a Lynx one.
The people that make them now is AussieSpeed.
Just type in aussiespeed into google and it will pop up.