Donger,
I can't tell you about the current status of the certified sketch program, but it was valid for several years. I have probably 6 or 7 of them. As you correctly stated, there is no info about certified sketches on the website. And the process was very similar to photo/lobby cards in that (if you were the witness) you filled out all the paperwork with the data and that was what ended up on the Yellow label. That is why sometimes you will see Sketch of ___________ by (Artist), because if the witness put detail on the form as to what the sketch was, it usually ended up on the label. It seems like easy money because they don't have to grade anything, so that makes me think they would still have it available, but that is pure supposition. I hope that you track down some info.