I don’t know what the “correct” length for the outer cables is but, with the two support clips fitted to the cam cover rear outer retaining studs and the release catches in place on the bulkhead the routing and overall length of the outer cable is pretty obvious. The brass adjuster goes midway between the two support clips so that gives you the lengths of the two pieces.
Edit:- Just found a Service Bulletin on the bonnet cable. If it was carried out on your car you may only have one cable support bracket not two - might save you hunting for something you don’t have 