It's unlikely that there are any rarities among those, and I can't see many collectors wanting to sift it. I have heard that the Royal Mint at Llantrisant are still paying face value to redeem pre-decimal coins, but I should think the cost of getting it all to Wales would be pretty steep. The highest value coin you have there is the 3d, which is about 1p face value, so I imagine the total face value is not very much. In fact, the metal value would be higher than that, but you say local scrap yards don't want it? More fool them - don't they know how much copper is fetching now? Getting scrap copper value is definitely your best hope.