My Brooks Champion Flyer is semi-permenently covered by a Serfas waterproof cover ( I got it at REI). Mostly, it remains covered to disguise the Brooks from opportunistic theives. (I also ditched the quick-release seat binder years ago). The saddles stays dry in downpours, but the fenders really keep things nice on the underside. The steel railed leather saddle has been in use for more than a century- I think you may be worrying too much.