Making a Mask (Punch)

For my mask I have been looking at Punch and Judie.

The mask will be made with Latex and have long, big, chin and large nose. I would like to colour it with the 3 primary colours. 

The way of making this is, so far I have made a mold of my face. By getting a friend to cover my face with Clingfilm (leaving a nose hole) and then they made a mold of my face with mod-rock. When my whole face has about 3-4 layers and is covered in mod-rock. I had a wait about 15-20 minutes for it to dry. Then I took it off my face by putting my hands up to my face like I'm crying, look down and gently pull it off. Then paint soft soap inside. Then I filled it in with plaster, wait about 5-7 minutes then peal the mod-rock off when its still a little damp so it won't stick. Then now I have my face mold. Now I need to build the clay up to make it look like Punch or enhance the fetchers of the face.