I am not sure what happened with the last cryptic thread, but I suspect it was pulled by its originator due to the fact that it "stalled" very quickly, and appears to have done so again! Threads such as these only maintain an interest if they keep moving. We have seen similar instances on other aircraft ID threads...once it stops, people soon move on elsewhere.
As for where the thread should be, as a regular on Silhouette Challenge I believe that is in it's rightful place as ultimately it is largely historical in terms of its content and is clearly aviation related. I am not sure how to place this one as it is perhaps outside of the forum's title, however I suspect it is in the right place to get the best level of interest.