FAA operators are not allowed to change the Crz CofG leaving the default value for flight. Pretty conservative and on occasion causes unnecessary concern over margins. CAA operators can use actual CofG's and therefore you should either work out what your CoG is or use takeoff CofG -5% which as mentioned earlier is the very most the CG will change in flight under the worst circumstances. As the CTR tank empties the CG moves AFT then FWD again as the Main tanks empty.
The picture on your Speed tape is more correct with the actual CG entered and thats what I care about when it comes to the crunch, or flying the A/C to the envelope limit should it ever be required.