I would have preferred for MTH to do the Santa Fe yellow bonnet scheme before re-running the Superfleet warbonnet. By the way Santa Fe did have home-built SD45 B units, but no FP45 B units.
I really like what SPSF and his dad did with their units. I simply cut the tank in half on mine, moved the side farther out and shimmed it down a little. Better than stock, but not as good as the efforts above. Perhaps at some point, I will get around to fabricating my own tank. Cutting the tank and remounting it is relatively easy to do, and you don't have to worry about the speaker, which is mounted in the body, not in the fuel tank.
The FP45 tank has the air reservoirs centrally-mounted, which is why I chose not to substitute some other EMD tank, like an SD45's. (That would work for a F45, however). I considered an Atlas GP60 tank, which had the advantage of separately-mounted air tanks (allowing me to center mount them), but it looked too short. So for now, I just did this modification to the factory tank (a few angles are pictured):