Ok
Here is the bracket laser cut from 6mm plate and bent to the required shape. It has an offset of 56mm.
Here are some photo's of it all mounted up. Ignore the hex bolt on the front mount as I need to get a longer cap screw.
As soon as I get the longer cap screws I will try the fit of my saddlebags and then send them off to be chromed.
To put the unit on or off you just loosen the bolts a turn or 2, slide the front of the bracket over the 2 front posts and then lower the back down on to the 2 rear posts.
Nip up the bolts and your away.
I will post photos of the finished product when all chromed.