@RRSignal:
As you can see from my earlier post, they are quite dark - we're talking damp gloomy Scottish Highlands, after all, and prefer my buildings to be naturally muted in colour rather than comic-book bright!
However, returning to the original Gmax meshes, I can see that I set the light settings lower than I would now, and I can fix that, though it would have to be for the whole set, which wouldn't happen overnight - I can see mesh faults which I now know how to correct, which I'd address at the same time, too. I've tried one as a trial - PM me and I'll send you the CDP: if it's on the right track, then I'll add the conversion to my to-do list, and produce a second, lighter, set.
(Just don't expect it tomorrow, please...!)