LOL. I'm not sure the effort is worth the payback actually, I could probably have got much the same with playing with levels. I don't think I'll make it part of the work flow.
Joking aside Cedric have you tried the contrast masking technique I discussed here. I use it a lot and have it saved as an action. it's effects can be lessened using opacity and masks giving it a local effect only.
Do like the colours you have got here - have actually done a version using levels that you could post for comparison?