The drones in the frames are not so much of an issue and will probably be taken care of by putting in the foundation less frames, its the drone comb/burr comb between the boxes that i really need to stop.
I have done some more measuring today and I think I have found the problem. It appears my boxes are to deep.
Here are all my measurements:
Frame rest: 16mm - 5/8 inch
From top of frame: 7mm - bit over 1/4 inch
From bottom of frame: 9mm - almost 3/8 inch
Box depth: 247mm
Frame depth: 232mm
Top bar ends(tapered): about 8mm in the middle
All these measurements equate to 16mm (5/8 inch) between the boxes. But about 10mm (3/8") is maximum bee space.
My boxes seem to be 6mm deeper than the standard 241mm.
I think I better find a new supplier of boxes.