Think the market for antique appliances is growing because the population at large for several reasons. First would be the cost for much of the garbage out there, that doesn't hold a candle in terms of fit, construction and quality to the "old" range their mothers or grandmothers had, which gave great service year in and year out. Another reason would be the sky high cost for such ranges as Aga, La Couronne ranges and their ilk, which do nothing more really than vintage Chambers or Meritt ranges.
You mark my words, as the Feds keep destroying the washing machine market with their kooky enery guidelines, your going to see more and more people seeking out the washers of their grandmothers/mothers.