Your cochins are regular reds, the extra black/white markings don’t really mean anything genetically. The blue hen doesn’t appear to be pure for the mottling gene, she just carries it. Both d’uccles are porcelain. You didn’t mention the barred one, are you wondering what would happen if you bred her as well?
Red cochin x blue cochin - blues with some red leakage and blacks with some red leakage (if using the frizzled rooster, half the chicks will be frizzled).
Red cochin x porcelain d’uccle - mostly solid colored red/buff chicks, carrying the mottling gene and the lavender gene but not expressing them.
Porcelain d’uccle x blue cochin (carrying mottling) - 25% blue chicks with red leakage, 25% black chicks with red leakage, 25% blue mottled chicks with red leakage, and 25% black mottled chicks with red leakage (all will carry the lavender gene but not express it).