Vintage Ad Browser is a new service that allows you to browse vintage
printed advertisments.
I'm not sure how dynamic the results are - many of the images seem to relate to Ebay auctions, and these auctions will
end, so I don't know if that then means the ad will no longer show up.
A browse around showed some interesting mill related results (though linking to individual items seems to be
problematic - the best I've come up with is to use very specific search strings):
Ads for mills
Ads showing Dutch mills
Others