It should held up really fine with a few more center sections rails as you say wideopen231, and a new bottom.
Axles where rated to 850kg each, total of 1700kg - enough to at least build a strong open trailer.
But I let go of the caravan chassis... by accident(i was on vacation). When i called back to actually buy it, it was gone.
Well, not any big problem.. I`ll find another.
Still on the look for other options.