I've spoken with the current owner of #10, she's on a Sam Keith fan page with me and has a complete set of 12.
According to the locals that I know that worked at Image, mine is probably the highest numbered surviving copy then, they told me that the rest of the pile was tossed after not selling and for having smudged signatures. It's therefore likely that there are a maximum number of sixteen surviving copies Maxximum (pun intended). Thanks for the info, I've been curious as to if their info was genuine, and if all of the known numbers are lower, then it's possible.