101? 109 I hope, Yea Military Chassis had some strengthening plates I think. Needs to be either, grit blasted £100 or spend a week with wire brushes and red oxide and chassis black. Leave it on the axles till you have wire brushed all you can get to then take the axles off, get out the old bushes, wire brush the rest paint, then re bush and the refurb of the axles can begin. Suggest you leave the rear salisbury internals alone until its back on the road to listen for noise. All you can check really is for any roughness. A salisbruy axle isn't quick strip and rebuild like a Rover axle everything is preloaded with regard to the axle casing so its a pain but can be done but best left until you need to do it.
There was a guy on another forum that has completed a Salisbury drum braked axle to disk brakes although I have to say that having a look today I am going to do things slightly differently to his. He used the wrong spacers (two types groved and flat as per the lock tab washers and stub axles) He used the grooved spacer ring on a flat stubaxle and ground the inside to go allow it to go furthur down the stub axle where it gets larger in diameter. Although it cannot spin its not a great fit but I guess It works for him. I will use the original 110 outter hub seal spacer and reduce its thickness to that similar to the RR one to compensate for the wider bearing spacing in the RR hubs compared to the 110 original hubs. Well thats the plan anyway! Jai