Pro-vantage, I will answer your question from a few perspectives.
For starters, your tallies of things like "22 wheats", "4 silver dimes", etc... do not necessarily lend themselves to indicating that you should have been in-line for a silver quarter, to begin with. What I mean is, that even in an absolutely virgin old site, it would not be unusual to get your kind of target ratios, w/o getting a silver quarter so far. You can not assume that just because random pocket change right now, in 2010, seems to be 5 or 6 pennies and dimes, to each quarter in your pocket, that those ratios must have held true back then in the old days.
When I first started this (mid 1970s), there was absolutely no "cherry picking" that could go on, because there was no discrimination (at least not viable or well-sold/used yet). And it would not be unusual to get multiple mercs, roosies, etc... before getting a silver quarter back in those virgin times of school yards.
The current ability to TID quarters (verses dimes, pennies, etc...) has only been around since 1982 (with the first Teknetics). And it's not very often that someone goes around strip-mining quarters, while leaving all else (although I suppose it's possible). But most old coin hunters would have little reason to do that, and would also dig the dimes, pennies, etc.... and perhaps pass only the foil, tabs, etc.... if they wanted to "cherry pick". I find it highly un-likely that someone went through and purposefully chose to pass all the dimes, in an area where they'd have suspected that the dimes etc... would also be as old as the quarters they were digging. It just wouldn't make sense.
The old all-metal TR machines would go deeper on a quarter, than a dime or penny. So in that, I suppose they might have had higher ratios of quarters, verses smaller coins, eh?