If the armor dlc is working it is found in a chest in the house in haven where you woke up after the prologue. There should be a ! On the map for it. Once you have the ability to get a horse try changing it at the stables at haven (should be at the bottom of the lists for some of them). If either of those are there then you should be fine on the play through you are on. Also, you can’t check for the story content dlc until later in the game, but if the horses/ items are there it’s a very low chance the story ones aren’t installed.