I see you're trying to avoid spray-on finishes. I don't know anything about wipe-on poly, but proper application of Tru Oil on a mahogany neck will leave the neck feeling like highly polished wood with protection for the wood. With a neck made of maple which is a much denser wood, I'm not sure how much of the oil will get absorbed, but maybe enough to make a difference. Another option is to not lay a finish on the maple neck at all. You can protect the maple wood by just applying a proper wax like gunstock wax.