Thanks for that Eddie. I was able to get some bolts/screws as you describe, from a friend today - they fitted of course. Regarding the paint layout, my concern was to establish the uppermost point for the line that sits between blue and black at the sides. Photos I've seen of the bike, now mine, previously my Dad's, don't make it clear, but now I'll be able to fit a pair of knee grips and be able to mark the line. My contour lines will be based on the observation that the line should pass next to the top edge of the grip, while at the bottom of the tank the line can be overlapped or not depending on the fit of the knee grip on the securing plate. As you say however, the layout doesn't actually follow the shape of the knee grips. Old photos from NCR and elsewhere seem to confirm all this. So, now I'm confident I'll get the layout right.
There is some paint from the 1970 restoration my Dad did, but not enough in itself to avoid the necessity for my research.
Anyway, I have an extra tank that is currently primered so I'll draw the lines on it and this I'll hand over to the guys restoring the tank so they can copy the layout accurately.
Hope that makes sense.
On the subject of knee grips, are left and right grips exact mirrors, i.e. of similar curvature and dimension? I ask this because the original pair I've been looking at this evening are not exactly the same. One is slightly larger than the other so that I'm thinking I may want to look through the boxes of spares to see if I can find an exact match... or not depending on what members say here.
Cheers,