Good points Steve.
The paradox is that the records are, as you say, sometimes worth big money, however for all people involved at the time (singers, writers, producers, etc) the costs were more than the revenue so in fact they were money losers. Can't really expect record collectors to pay a commission on top of the purchase price and give to the artists, writers, producers, etc (even if you could find them).
When I win the Spanish lottery (last time was £110 million) I will get every NS artist, writer, arranger, producer to the UK and have a massive "meet & greet" (probably at a rebuilt Torch, Mecca or Casino ;-)
About 5 years ago I did something very much smaller, on my own, when I tracked down the Ad Libs, Chris Bartley & The Spellbinders and got them all together for a day in New Jersey, wonderful day.
The truth is the only money to be made in NS is with record trading and perhaps and I say "perhaps" with one or 2 promoters.
Chris L