The cards that were in the game originally were made specially for the game.
The fronts are 74 fronts, with a couple pose differences between the regular ones and the game cards. The backs usually have slight differences often a little as a different number of asterix in the copyright line.
There's a good checklist here
http://www.footballcardgallery.com/s...rker+Brothers/
I've had 3 or four of the games, and if I remember correctly eventually the complete set, but probably not all the variations within the set.
Steve B