Attached the back rail. Near complete with the perimeter except for the small front rail that will tie in right at the junction from tongue bars to the angled sections of rail.
Then started dorking around with placement of floor support bars to see if I need one more. Ill probably try again tomorrow now that I have a better idea of axle placement. I'm rather amazed at the strength of 1.5" x1/8" steel angle for being less than 1.25lb per foot. Though I bumped it up to 2" angle near the spring mount points to better handle the racking forces in turns.