Originally Posted by BGTV8

I have mine on a strap of steel mounted using the two bolts that secure the front legs of the drivers seat frame to the bodyshell.

I had to make up a spacer to lift it by ~6mm to clear the frame indentations and then bolted the metal bracket that comes with the extinguisher to the steel strap.

This was a piece of off-cut scrap steel 20mm wide and 3mm thick which I got from the local steel fab shop which needs to be (from memory) around 420mm long (or maybe the holes are on a 420mm centre - cannot remember, but it is simple to measure).

The bolts securing the front of the seat runners are 12mm.

Took me about an hour but then I have a drill press in my shed which helps.