Have a look at the ' 1 smart missile' insert...
Plus IIRC there are a few slight variations in colour with certain inserts.
Cool mines a prototype as well then. I always thought that it was just early production, dog of a thing to get the t-rex running right 100% of the time.
My Dino was missing the L/R motor, and there were other problems contributing to the Dino not functioning after installing a new motor. Out of all the games I've done, the Dino is the hardest "toy" to have fully functioning. The BEST thing you can do is upgate the game ROM, this has a modification that prevents the wear on the L/R motor.