Sorry but the default skins for each ride are built into the game download and can't be updated by skinners. Hitech would need to replace it with another B-25C skin, adding this new default into a game update for all players to download. He could then put Quitch into the list of skins that can be adopted by skinners. Its a fair bit of hassle for him though, so I don't know if he'd want to do it.