I'd love to get my hands on one of those! When it's solved, is each face specifically... 1 2 3 4 5 6 7 8 9
It could be either easy or hard depending on how the various faces are oriented with respect to each other. For instance, if there are two corner cubes that have three '1's, then it would hard to know which one goes where.
I'm sure there are generic Rubik's Cube programs out there that let you plug in your own pictures to map onto the faces. If not, then someone should write one. ...perhaps in Java? All you would need is an image of a 1-9 square of numbers. to paste onto each virtual side.
I picked up one of these bad boys for cheap at the local drug store.
The digits are arranged as follows:
That diagram even shows how the digits are oriented.
This means that on any corner piece, two of the digits will have the same up vector and the third will be at a right angle to the first two. If the third digit on a corner piece is on top, the piece belong to the "Top" layer. Conversely, if the third digit is at the bottom of the other two, the corner piece must be from the "Bottom" layer.
A similar analysis can be for half of the edge pieces.
That amount of analysis should get you all started.