AgB - I suppose that could be an option - provided the person hiring, covered all the costs & a bit more for the Ross revenge. & Mike, of course DAB on a wider scale might be an option, though the costs are pretty prohibitive - I don't think any of us, would want much of every hour, saturated with adverts & sponsorship stuff to pay for it, do we?
We must hope the Solar cell powered 648, at a higher power. is the right answer - perhaps with a lesser populated MW, the bandwidth will be able to be widened somewhat - though not that many modern radios, could take advantage of it - old valve radios, would sound good, though
Here is some Mark Mathews from the 1980s (My old mate Peter)
http://keepfreemusic.com/offshore/mm558.mp3