Thanks to Alex's accurate measurements and brilliant CAD drawing, I finally got the missing brackets fabricated - amazing what you can do with a vice, a hammer and an angle grinder!
Throttle bracketry.jpg
Just missing the bolt to hold it to the manifold so thought I would check with the wise before I knacker the thread - a 1/4 UNF only goes in one turn so I'm thinking UNC for castings?
Hoping someone will know....
Richard