dredge are humanoid made of metal, for the sake of simplicity, they are simply Half-construct (7 RP). Personally I would use the warforged by default.
-Large (7 RP)
-Humanoid (Giant) (0 RP)
-Base speed: 30
-Ability scores: +2 strength,+2 con, -2 dex, +2 Wisdom
-Ancient foe (3 rp) Dredge Varls gain a +2 dodge bonus to AC against Dredge and a +2 racial bonus on combat maneuver checks made to grapple Dredge.
-Languages: Common, Giant
Give the varl the dwarves favored class bonuses.
Menders are wizards. They just cast spells to repair armor...which wizards can do. Now if you want to see it more like healing, Make them witches(without familiars), since armor breaking is generally not an issue in dnd games or use the arcanist archetype which uses the witch spell list.