Matt,
Kab is coming along nicely... looking very shiney in its new paint! Spend lots of time tip-toeing around it not scratching paint!
Not sure about the welding or heating of any steering component being an MOT failure. I worked for an MOT station for a while and its not one I've come across. I'll check it out with my old boss and he can dig out the book
We have lengthened the steering arms by about 50mm per side. With anti bump steer kits fitted so that the track rod enters the spindle from the top, the angle of the track rod is almost identical to that of the bottom arm so pretty good.
If your wheels catch on any part of the car on full lock, its an MOT failure.. I know that much and I'll be looking to sort that out. I've only just dropped the car down on its front suspension and not tried the steering on full lock so we'll see how it goes.
MG