Once you get them welded up you will still have to profile them. We have an old Black & Decker that I did a test using the fittings for this job. While not real precise would work in a pinch. After welding up and profiled, probable should have them surface hardened. If you don't have the tools to profile, check with an automotive machine shop. Even the one we used just got a new one so it is still being done.
When I rebuild these rocker arms, I use Nickel 55 3/32 welding rod. Before I weld them up, I put them in an old toaster oven on high broil for a couple of hours and then weld one at a time. Once they are all done, I heat them on high for a hour more and then I slowly cool them down. This I believe lessens the chance of cracking on the rocker arm just behind the pad. I made my own tip profiling attachment to fit on an old Van Dorn valve grinder which seems to work very well. Attached are a few pictures of the last set I did a while back.
