Car restoration could be like life and a deck of cards; you play with what you're dealt. Alex and RJ have weighted in and my friend Glenn who helped me find the fastback have all agreed that the gaps aren't that bad and there are some work-arounds. So that's the direction I'm going to go in and ditch getting a new floor. Like Alex commented, "Metal is metal", right?
So here's what I'm going to try. I have some small pieces of the floor leftover from trimming the edges with the air saw. I'm going to experiment with the "Alex method" of using those pieces to fill the gap and then grind off the excess. Then I"m going to try the "Glenn method" which is to take a piece of small diameter wire, like 1/16" or 3/32", and tack that in place to fill the gap and then grind that flush to the floor. I'll swing by Thrifty Supply on the way home and pick up a piece and then let the experiments begin. I promise I'll document it all with photos for the next person with the same or similar issue.
That's what I love about this blog and others. Everyone gets to learn from each other and get support to carry on. If it weren't for that, I'd probably be ordering a new front floor today.
Thanks guys! I appreciate your encouragement.