There have been credible claims of a handful known to be out there with collectors, in particular Web of Fear 3 seems very likely, it would likely be a number in single digits if there are any. The problem here is that it says there are 97 missing (true), but then could be taken to mean all of these are missing because collectors have them. Rather they are all assumed to have been destroyed, but it is possible a small number escaped that fate and are still out there in the hands of collectors