I expect that they mean repairing elongated or damaged bolt holes etc...not that a wheel CANNOT be built using welding. They just want to keep unsafe parts from being reused.
On old steel wheels the centers are either welded in or riveted in, I dont see how welding on a rim is a bad thing. Ive never welded a rim but I dont see why it wouldent work or be safe. As long as your a good welder then it should be just fine. If not your wheel will come apart and youll be changing your pants.
So there is more than one way to skin a cat... The picture will tell you the direction I'm headed but my "spud" has less than .002 run out, which is good enough in my book. I will be mounting up my rim over the weekend to split it and will post a new thread on the whole process...
If you have access to a milling machine you can use a parting saw and cut the wheel with that .That is how I cut things like oil pans and others that I want a nice clean and straight cut .