[Modeldad]

It is quite possible that the aircraft were F-8s. I belive that at the time many of the 74/75 uppersurfaces received an over painting of "green" (or Farbton 81) in a random manner. The result could be that the crosses were left on a lighter colored background, appearing as a defined area.

Perhaps some of the green was brought in around the upper wing cross, making it appear smaller.

Note that the report indicates crosses applied on a roundel, not that the roundel itself was the marking.

There appears to have been no confusion, as the aircraft were identified and shot down.