Humber FV1600

[Richard Coutts-Smith]

Hi all Humber experts out there,
Can anyone tell me how to get oil into the outside tracta unit for each wheel? Inside unit has its own fill plug, outside unit appears sealed. Possible that it feeds oil through from the diff when mobile, but certainly does not when stationary, and not game to try. (Have one hub open to see if oil comes in from diff or inside tracta joint). One pic in the drivers manual shows a plug at the side of the hub, but this does not exist, and no mention is made?

While I'm here, does anyone know what the bracket in the first pic is for, only seen it on Aussie ones so far, the only thing I can find to fit are the flat sections that are part of the canvas framework(As Shown). Inside the tub are a set of straps which have me puzzled as well(2nd pic).
Any help greatly appreciated as always
Rich