You can stain (no buildup) and put a very thin/diluted coat or two of finish on everywhere before putting stuff back on; probably not necessary, but I like to know there is something everywhere, for those days when water pours down the barrel and into the barrel channel, for example. The BP and Patchbox, esp. need to be on when you apply finish, as they will likely not fit right later if the finish builds up, and the finish will close up many small inletting gaps for you, also.