Nice to see you in the garage, sorry to hear it's not a good day thoughMessed about with some tubes today to see what the back-end tube arrangement will look like.
I am not too-sure the pieces at 45° will clear the chain that runs between the output from the IGH and the input to the 2WD unit.
I think I will stick with this arrangement and then mount the IGH on a frame under the diagonal tubes.
I think it will be OK and this triangular shape will provide a good platform for mounting things.
I had to stop because I am having a "painful" day today, and I don't know why.