Iv had good luck with using car filler (extremely strong bond) and if you don't want the filled parts to be permanently pink I usually leave 4-7 cm dip in the full and then use a wood putty build up of about a quarter inch then sand it down to fit the curves! Good luck m8
@mikehalemashak where were you thinking of cutting btw. If I was in your shoes id actually cut into the cracked area some and then repatch the new nose! Hope all goes well and if you have any questions throw me a message!