These days communication and the selling/buying works a lot quicker doesn't it, and therefore people get in a tizzy. Things were slower in the 60s when coin collecting took off (people old enough to have been there may be able to verify), but it was the same principle, e.g. I think 1950 and 1951 pennies were comparatively more expensive back then than they are now. Some would say they are as a result of the 60s still too expensive! And I suppose in the last days of the old money there were a lot of potential 'rarities' over the past 100+ years and people knew that when the decimals came in there would be no opportunity to check for the slightly scarcer coins, so everyone kept them which probably made them harder to find. As a result of that there are still tons of low grade 1912/18/19 H/KN pennies and they're probably more plentiful that the non H/KN, simply because everyone kept them and the rest got melted! I'm always surprised by the volume of pre 1947 silver coins that come out of the woodwork too, often untouched in sheds/attics for 40+ years until the person that originally put them to one side dies and the heirs discover them when clearing out. I think 90% of all the stuff I get offered (the low grade toot) was originally accumulated in the 60s. I've even heard on more than one occasion first hand, that bank managers were advising customers to keep sealed bags of 1967 pennies!