I think Les has the answer. Looking at the prints, I am certain that post flashing will do it. I have also tried pre flashing then burning in which is much more effective once the pre flash has pushed the paper up to its threshold. You will win eventually; good luck!
If lack of time is an issue...
Pre-flashing is one of the sympliest technique (and by that also the strongest)to improve the highlights in your print.
It can easely done with almost every print.
Rh-design sells a beautiful tool for that means.
A 'must have' in almost every darkroom.
You can test the effect with a stouffer tablet.
At 1/3 to half the time of creating "fog", you will see that mid-tones and shadows are not 'attacked' by this technique.