Jamie.
If you want others to help you, its a VERY GOOD idea to show you have searched and tried your best to source info first.
As for the gauge not working perhaps Martin Young could help if you ask, its all down to showing you maybe able to return the favour .
Kev.
ps DaveH may put diagram back on his server if you ask,i did not know it was not there any more as its was all from (my) this old git,s memory