Okay, here are some detail/daylight shots.
To try and answer some questions:
I think the benefits of the Mototwin headers are purely aesthetic, although combined with their peashooters they really let the motor breathe and have a bit better ground clearance. - nice classic look and sound too.
The riding position is more stretched out than standard but the bars are a bit lower too so you, kind of, 'wrap around' the tank. I may need to think about rearsets or jack up plates though - we'll see after a long ride.
No idea about tank capacity yet, I'll fill it on the way to the test centre and let you know. I plasma cut the brackets for the gauge pods from 2mm stainless and then bent them up. They fit over the fork legs and have a little tab so I can fasten them to the old handlebar screw hole under the top yoke. The clip ons then clamp them in place. I guess you could do the same thing with standard handlebars in place. I also relocated the ignition switch to in front of the top yoke and fitted the warning lamps in the headlight shell.