Oh, I don't know. I've had some cars move my soul. Some in the wrong direction, too.....
You will probably not have much luck trying to rebuild these a-arms. The "tubes" are actually threaded and accept threads on the fulcrum pins. The most common fault is that the pins become seized in the arms, and when you finally separate them there is nothing left worth saving. You'll almost certainly find the kingpin is loose on the pin, but is trapped by the aforementioned seized parts. If this is the case, don't wast time and frustration on the offenders. Remove the top trunnion and slide off the swivel axle (spindle). These are the parts you want to save.
The kingpin is going to be included in the Major Overhaul Kit, along with the bushings in which it rides. Pay careful attention to the orientation of the old bushings with respect to the alignment of the lubrication holes and the installed depth. Then remove the old ones. If you don't have proper mandrels, have a machinist install these for you. If you go this route, bring him the swivel axles with the old bushings still installed and point out these things to him. He probably already knows about the lube hole thing, but the depth is critical. Make sure he understands this. Get yourself a manual if you don't already have one. Go through every step in the reassembly process to the letter, making sure you get the vertical end float just right. (ask davey) The stepped reamer in the Moss catalog is for sizing these kingpin bushings. Without it the job becomes much more complex for the machinist. You can't do this part yourself if you don't have that reamer. I know it's expensive. We guard ours jealously! If you find a shop that specializes in Britcars, they may have it. By all means, this is the preferred route for correctly sized, and perfectly aligned bushings. Let us know if there are further questions.
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon