Lawrie, on a side note, the wings look very well mounted.The wings of standard 4/4 look not so well mounted, they look lifted at the outer side.
Heinz...I used to work at a radiator producer. A rad with a gap in it to allow some air through could be done BUT....
It would require a radical redesign. The gap would reduce the area for cooling engine coolant by the rad. Hence either larger rad area or more rows of tubes and different gills format to compensate. Also the flow through the rad would be interupted by the "hole".
We used to make some one-off rads for weird and wonderful uses not just auto use.including refurbishing a core block for a Spitfire (plane), but nothing with a"hole". The hole is like putting an obstruction in front of the rad.. A bit like blanking off your rad for winter use to prevent too much cooling.