One is shown above, and Roy pictured them a few days ago.
Royal Mail simply reprinted the two original stamps and added the necessary elements for a modern postage stamp - the Queen's cameo and the service indictor - by slapping them in the upper right corner. The end result looks like, well, something I could have done.
I'm trying to decide how Royal Mail justified these stamps. My guess is they wanted to come as close as possible to allowing people to use the Penny Black and Tuppenny Blue.
Personally, the stamps look to me like defaced versions of the originals. Plus, Royal Mail couldn't be bothered to use recess printing, not even for the souvenir sheets. The other postally valid commemorations - the Wilding castles, the Seahorses, etc. - were recess-printed, but the Penny Black didn't warrant such treatment, I guess.
For a much better and updated design, here's the recent Penny Black anniversary stamp from the Isle of Man. And yes, it is really selling for 1p.
I have really enjoyed Royal Mail's previous recreations. Other than the artificially high face value, there was nothing to complain about, and even that can be partially justified by the cost of recess printing. These Penny Black and Tuppenny Blue reprints are a real disappointment.