Wow, super clean too! It seems Spandau, 1888 is a very common year for these rifles. My 71/84 is a real beauty though she has lost much of her original bluing but the bore and overall condition is unbelievable for her age (and considering she used a cartridge that utilized black powder!).
You have even have a brass muzzle cap you lucky dog you (even unit marked)! Now I'm jealous.