Cresote oil is effectively free with time investment. You turn Coal into Coal Coke (twice the burn for no additional charge!) and get the oil for free as a byproduct. It actually comes out to less resources to do it via railcraft, considering you're making 16 at a time, rather than 8.
However, there's a simple solution:
If you'd prefer to use the vanilla recipe scheme, just open the railcraft.cfg file and set the tag "tweaks.rails.useOldRecipes" to true.