Undy,
You got a really nice fit with very little gap between the collectors and primaries. The TIG man will be very appreciative at that. My first set I had to cold work the collector to mate with the primaries, because I couldn't fill the gap with the filler rod. My second set is right there at the primaries and will be an easy weld.
Good luck as I think you'll be happy with the look and performance. What muffler did you go with?
Here's eventually what you're getting yourself into as far as the look. Not the collector for the purest, but it sure ain't bad.
I'm in the midst of doing a set in polished stainless now. I should snap a pic of my collector in process
R