There are many Sweet Caporal combo's that are far tougher than most people would think here's one example
Sweeney SC350 factory 25.jpg
There are 3 Jeff Sweeney Drum's in the PSA pop report but there are only 2 SC350 factory 25's.
Cardtarget only lists 3 sales of this combo since 2009 and 2 of the 3 sales are the same card that sold twice.