As previously noted there are a large number of men who have tested STR markers at FTDNA bearing a signature of the CTS4466 SNP. Of these three of these closest to the middle of the phylogentic tree have tested CTS4466 positive, and two of those S1121 positive. This helps to establish the accuracy of the prediction from STR markers alone.
At this time one of these individuals has a DNA sample undergoing Next Generation Sequencing at Full Genomes Corporation. These results should be returned in the next three months. After comparing with the existing Big Y tests for CTS4466, this will show where the next round of SNP testing should be focused.
A more direct option is to find a second volunteer from the identified list take the Big Y test. Should any of the central kits listed in the phylogentic tree be interested, they should contact me through the Cain Surname project for details.