Yeah, awake now. Both visually legit. Series A and Series B bars is what I call them - there are earlier designs. New dies. In late 2013 or thereabouts PAMP started prefixing all of their bars with a B, and introduced a bunch of refreshed dies/designs. XRF *can* test through an assay card without destroying it - the card itself has its own signature that shows up on an extended XRF examination (20 seconds +).
Thanks, that link shows both A and B series, and comparing the differences with mine they are exactly the same. i.e It's safe to say the bars are legit, and PAMP have changed the designs slightly from series to series.
How about contacting PAMP? Write them an e-mail or something. 0.5 g difference is not that much, considering the fact that it's sealed inside plastic. Perhaps that plastic material differs slightly or, the plastic's dimension have changed. Check both items (and compare) the shine, the colour nuance, the edges of the bars - how rough are they? A PM tester device could help a lot.
I hope you can access a XRF and do a examination as suggested by goldpelican before have to chase this up.....
Look at the hands and particularly the thumbs just above fallen coins! The one on the left looks well odd
