Case for 3,1 identical to 1,1? Considering Heart Transplant!

Hi all,

Does anyone know if the entire outer case of the Mac Pro 1,1 is the same as the 3,1?

I bought a 3,1 (2008) very cheaply as it had been dropped in transit resulting in a deformed top-rear handle. It hasn't affected the machine in the slightest but is unsightly.

So I'm wondering. Could I swap the innards of my Mac Pro 3,1 with the innards of my old 1,1 (2006)? All the ports are identical but I'm just wondering if the motherboard fixings might be differently arranged.

Any help would be much appreciated!