After securing the two halves of the plaster cast with duct tape, you can begin to fill it with latex.
Four or five coats later the mask was carefully removed.
I am very pleased with the result. Although, after a few days the colour of the mask darkened to a sickly orange. I would have prefered it to have kept this light flesh colour as this is close to the actual colour of the character.
The excess Latex is trimmed with scissors and eye and nostril holes are created before wearing.
Although this has turned out better than expected, there are still many imperfections and discolourations to the mask. This gives me the idea to create some sort of zombie Kryten costume. Possibly even a zombie version of the entire cast of Red Dwarf, if I could get some friends involved.