Yeah exactly, I'm 240lbs.
mostly muscle... but yeah, that could work, but the only problem i can see is the lengthening part of it. You'll have to lengethen the actual model or risk not having the parts fit.
Also
here is my unfold of Clayton's right shin guard. I don't recall anyone unfolding it yet so... also, it has probably more parts then it needs, I was going to ease of assembly and not # of parts.