1966 Topps Rub-Offs Set - 80% Complete

I just picked up this 1966 Topps Rub-Off of Eddie Fisher, it is the 96th one I have gotten which means that I now have completed 80% of the total 120 in the set.

Most of the remain ones I need are very difficult to find.  They do not come up for sale or auction frequently and end up selling for a higher price.

These rub-offs were printed in rolls of 20 and my theory is that one of the rolls was printed in shorter quantities than the others thus accounting for the difficulty in trying to acquire the last 20.  Just my own theory.