Let say I stick with new Monarchy and want the hand cannon, but my vendor is not selling it, so I rank him up to rank 5 or 6 and it appears. If I do not like the perk rolls with that hand cannon, can I continue to rank up to a higher level and have the gun they're selling reroll? Or are all the guns sold by faction venders locked to specific perks, regardless of how much you upgrade them or when they show up.? Help appreciated! Thanks!