I tried to look up my 1964 D Slabbed Roosevelt in the PCGS registry, however there is no results? It's an older "rattler" slab. Could that be it? Number on the front: 05129.64/7000023 I typed in only the "7000023" like I was supposed to.
Check the numbers again and see if you're not adding/subtracting a number. Do you have a photo of the slab/coin?
Thats a "Sample Slab" cert number. Its not a valid cert number and therefore would not show up since hundreds of them were made. Ccheck out this website: http://coins.ha.com/sampleSlabs.php?type=pcgs You'll see that more than one date has that dummy sample slab cert number.