Bedford CF2 4x4 Project

[Scotty2]

Thanks to the "Why no love for Vauxhaul Bedford" thread, I finally laid my hands on a FF transfer box. I hope that it will bolt on to the back of the existing 4 speed. Tried to post on CF forum but failed. Does anyone know where I could get a manual or guide to servicing it? Is the "Dow" fluid in a sealed unit and I use normal gearbox oil in the sump?

Anyone decode the casting numbers?