Ivor, your idea of rods built into body connected to end plates sounds interesting, not sure if that would help with cabinet drop by strengthening body,for those who obsess about it but most of us don't even notice, or cause tuning unstabilty with expansion /contraction of metal as a side effect.Having more metal for vibration to pass through could well have a major effect on tone,a down side would be adding weight.Some of the MCI guitars built by Bud Carter,had welded metal frames on underside, and although I know very little about this personally, believe they are a much sought after guitar , as it is stated it brings them very near the so called p/p sound.Sierra guitars had a similar type of set up I believe, also I understand body panels were metal, so there does seem to be some credibility for Ivor's suggestion.One other thing that puzzles me is the design of the new Rittenberry, with features such as round cross shafts, which makes me think why would anyone go back to this with all the problems of bell cranks slipping? Do round shafts resonate better than the square ones, if so why?
I don't know if a one piece metal body would be answer, but if it hasn't been tried then who knows, and might be worth trying.I can see downside could possibly be a weight issue, the reason I sold my Mullen and went for the best quality light weight guitar I could find, as back problems meant horrendous pain every time I had to move it around and set it up.
I know Uncle Ken and I have our little battle over body material, but no one can doubt the quality and standard of engineering on MSA guitars, (as Ivor said these guys build high end aviation parts, on my factory visit I could not believe the standard of work which went into guitars) , which I personally believe to be the highest standard in the Steel guitar industry, does that extra refinement make a substantial difference - who knows?
At the end of the day does the average punter notice -- NO , most don't even know what a steel guitar is, let alone the difference in tone between a good one or bad one or any particular make, it is just players who do, and I believe a lot of that is misguided and comes from a certain amount of snobbish beliefs and myths built up over the years-- that should stir up quite a few of you. if a guitar sounds good it doesn't matter what make it is, I still believe a great deal of tone is in the hands of who is playing it.

MSA Millennium SD1O, GK MB200,Sica 12 and Telonics 15 speakers , Joyo American Sound pre amp, Jay Ganz Straight Ahead 500w class D Amp, Hilton pedal, Peterson tuners,Digitech RP150,Scott Dixon seat/ flight case.