John,
I was lucky enough to visit the factory in Ft Worth where they were (initially) building the replica ME-262's. They had several fuselages in various stages of completion, and several sets of wings still in the jigs. The engine mounts were the most interesting thing though. The wanted to keep the mounts as close to stock as possible, but the little GE turbofans they were using to power them are probably 1/4 the size of the original Jumo engines. Their solution was to cast large aluminum cases with the outer dimensions (and mounting points) of the Jumo 004, they were cast in two pieces like a clam shell, and bolted together around the GE engine. It had the added benefit of helping keep the CG manageable.
They also built replica cannons in the nose that were similar weight to the originals.
It was a very interesting visit.
Less than I year after my visit the project ran out of money and was shut down for quite a while. It eventually was moved to Washington state, and I think they completed four flyable airplanes.
I think I have some pictures scanned into photobucket. I will look for them later and post if I can find them.