Thanks for that, that reinforced my initial thoughts from what I've read.
What are the chances of getting that photo posted on the board.
I have managed to find a completely original 18RGU that has just come over from Japan. I don't know what it was from but it is a real mess with emission control stuff.
You can hardly see the block for the tubing and valves.
I really hope that all 18RGUs did not have the same set up.