Posted By:
BobPeter,
If you go by the PSA Pop report, the '69 Topps WL Mantle is four times rarer than the same card with yellow lettering. That's probably a pretty accurate gauge since one would figure that gradable Mantle's would be submitted whether they were WL or YL. With 643 WL Mantles graded, I definitely wouldn't call it a scarce card (far from it). It's just scarcer than the yellow letter variety.
Bob