@orbeas. The rear brake cable has to run on the driveside before looping back to the non driveside to go into the rear brake. Hence why it seems so long, it needs to be for the braking to be smooth. Not sure why roberts put the cable guides on the driveside to be honest.
And the saddle doesn't look level because the ground is sloping.
He will have put the cable stops to match the brake calipers that were to be used, which would have a right hand stop and adjuster. not like the campag ones fitted. I would think that the frame would have had open brake cables with the right hand lever going direct to the right side of the top tube..