Year later update
A year later update. After a year I still haven't gotten everything in place inside the barn but it's very functional. I'm also very happy to report that after a year there are no cracks in the concrete floor. Several on another forum questioned the way I poured the slab especially for not scraping the grass off before spreading the gravel. But it has worked out well so far.
Since I said that, I'll probably go in tomorrow and have several cracks all across the floor but my red clay has held the concrete up just as I though it would.
One thing I wished I done different while I had the builders on site would be to insulate the side sheds where the implements are parked. I also use that area for painting, maintenance on my beehives, sharpening mower blades etc. It gets hot under there in spite of being open on three sides.
Of course, insulating is something that I could still do but.....