Captjack,
Is the beveled edge of the hardened steel parallel and in contact with the ground? Hard to tell from the photos but it appears you have it facing up?
Nice work so far, the next one I build will be with 4x4x1/2" angle iron too.:thumbsup: Mine is more complicated than necessary, I used 1/2"x8" wide flatbar set at 45 degrees and have 3x3x3/8 angle iron bracing front and back. Super heavy and very rigid but overbuilt. I used the 6" wide double edged grader blades 5/8" thick to build my 8' wide grader plane.
I think you will like the long runners that is one of the key parts of a good plane.:thumbsup: