indeed, it's coming along very nicely and looks great. I have used por-15, too, for the floor in my past build ups. And I plan on doing the same thing with the floor with my current 73 beast. But after I repair the cancer in the normal spot on the driver side floor body mount area.
I agree with Scout-it-out about the bolts for the steering box. I use no less than grade 8 bolts for that. I might even suggest adding a reinforcement plate to at least one side of the frame, if not both sides. Ihon sells a 1/8" thick steering box reinforcement plate just for this application.
rpt Scout II steering box reinforcement plate. I actually made my own out of 1/4" plate. The frame on my my 74 Scout II was getting a little tweeked right at one of the steering box bolts. And I have actually watched the steering box flex a little bit while rotating the steering wheel. I have seen and heard of people fabbing up a crosse member piece that attaches to the inner frame rail where the steering box mounts going to the opposite frame rail, kinda like the trans mount bracket. Food for thought
other than that, loven the progress.