You do have spare boards, don't you?
I have another set of boards, which I have bought to put in a boat, but they didnt have any wires attached so I had to pull the Tiger apart to see what went where.
I think all in all, the best (cheapest) way to go if intending to use Heng Long gear in a boat is to buy the complete tank and control gear to start with.
I should have costed it up better before I started buying bits.