Hi. I have a lvl 43 cleric and I met a guy who had a pair of "Black Salt Shoes" (lvl 35 mage shoes) and he said they had 7 luk on them clean. He doesn't remember where he got them and now i've been on a search to find out. and no... he never got them off Fire Boars or Propellys (according to bbb.hidden-street) because he said he never killed those mobs.
You can also check the library, which confirms that they're only dropped by Fire Boars and Propellys. He could have bought them in the FM, or looted them without realizing he killed the mob.
