If what you have is from this insert set AND if they are in fact numbered, I'd suppose they'd be just like the base inserts and be found on the upper left hand corner. According to the checklist they should be JC1J, JC10J, and JC15J. Do you see those anywhere on the card?
Also, if they aren't these, then I'd suggest you use the Mystery Card forum and upload scans for us to see.
Follow my blog - I Identify as a Card Collector.
“Aslan didn't tell Pole what would happen. He only told her what to do. That fellow will be the death of us once he's up, I shouldn't wonder. But that doesn't let us off following the signs.” - Puddleglum in The Silver Chair by C. S. Lewis