Mike,
I have a 145A mig. The certification company here in Sweden (SFRO = your IVA) wants you to make sure the mig you use to weld the steering column extension is powerful enough, and for that they ask you to try cut the original steering rod just by melting it with the mig.
My 145A MIG at full power did the job. See pictures in the middle of this post on my blog:
http://vouchtroadster.blogspot.se/20...-column-2.html
So bead welding the edges and plug welding the extension tube at three different points at each end of the extension (as they require) was OK with this mig. And note that my extension tube had 5mm walls. See pictures on this other post of my blog:
http://vouchtroadster.blogspot.se/20...g-column2.html
So, I don't know how powerful is your mig, but it might be enough to do the job.
Eddy, plug welding your extension might be the safety solution you are looking for too
Hope this will help