look at the websites for the various new-build steam locomotive projects. You need primary members with serious money, people like Pete Waterman, and you need hundreds of members paying not insignificant sums for a decade, and then you need tax concessions which are increasingly under pressure.
THEN you have the technical issues like casting and forging very large items which we simply no longer have the ability to do.
Engines like the Kew one survive precisely because they were kept in complete condition, and in some semblance of working order, for decades after there was any real commercial reason for doing so, and this doesn't apply to mine engines. Previous comments about the horizontal winder at Crofty illustrate this; it remained in use because it continued to be useful. I don't doubt that it would have been scrapped if it had suffered a major mechanical failure.
Robinsons' engine has had many decades of plain neglect from an owner who had no useful reason to maintain it; it would have been scrapped long ago if it wasn't in such a difficult location.
I last saw it in the mid-1970s when it had stood unused and uncared-for, for twenty years, having last steamed in 1955. It has stood for three times that period, by now.
There is also the basic problem of the nature and attitudes of so many of the people in the "heritage industry" ( stops briefly to wash out mouth with soap ). These people have no idea whatsoever of the actual nature and function of the relics which form their raison-d'etre. Who is more "authentic"; a student on a "soft" degree wandering around in a polyester "miner's costume" or making batches of candles with schoolkids in a preserved Victorian school-house, or a self-employed tipper driver contracted to ARC, eating a bacon sandwich and reading The Sun in his cab, in a layby off the A515?
''the stopes soared beyond the range of our caplamps' - David Bick...... How times change .... oh, I don't know, I've still got a lamp like that.