Stuart,
You were right on with using flux core and shielded gas. Not that I ever doubted you :-)
I went to my class last night and the instructor seemed a little baffled at my question.
"Of course you can", he said. I also asked about the quality of the weld and if it was as good or better. He said it’d be as strong and look smoother. Everything you said in your post. I just wouldn't have ever thought to do it that way.
Thanks again
Jim