update:
Well, maybe I'll reget it later on but what's done is done. I welded in the steel floor yesterday. I'm planning on use bed liner inside the tub as well as underneath. Hopefully it won't be too noisy but I gotta think, my flatbed minitruck had a steel deck and the floor in my reskinned 40 was the same 16ga. that was lined both sides and it wasn't noisy. I may get some dents in the steel that I wouldn't get with a wood floor but o well.
So after cutting the sheet to size I needed to "clearance" it a little around the welds for the tub frame and the tie downs.
Here's a couple pics where you can see where I did that.
All fitted and in place.
Stitching it to the frame. Pretty much did this around all corners.
only other thing I did was cut down a ubolt to use as a tongue handle.