While the HiT Flip Face Percy never got an official release, there just happens to be a well made custom solution! It was made from a Japanese TOMY Percy, giving him the extra detail he would've had. There's no battery car and he only has one (revolving) switch for the face, but it otherwise works the same way. For the only custom Flip Face engine I've seen, the execution is remarkable. Made by garigarigari.
There's also another one with a Flip Face James face and smokebox (and a battery truck), but the only video I found was a "making of" without footage.
There's also another one with a Flip Face James face and smokebox (and a battery truck), but the only video I found was a "making of" without footage.