I really like the end profile of your WB, it's one of the more unique spine shapes that you come across. The scales are unlikely to be wood, I'd think it was horn. It can look grainy when the natural fibers start to show from wear and drying, despite its ability to shine up like plastic. The neetsfoot oil suggested is a natural cow product that rehydrates horn. You can find it in hardware stores (particularly in rural areas) or Co-op and certainly a Tack shop as it is used to condition saddles and other leather goods.