Congratulations on your first MK bag and your first Hamilton. I don't use anything on saffiano leather except a leather cleaner when it gets dirty and leather conditioner once a season. I'm also a bit of an outlier, but I hate when the key fob slides along the bag handle and don't like tying it to the D ring of the handle because then it gets in the way of the handles folding flat. I attached a small key ring to the D ring of the handle and then attached my key fob to the small key ring (leaving it tied around the bag handle) so that it doesn't slide down the bag handles when the bag handles are down. Pretty anal, I know, but it works for me.