hey,there is a little mistake in the armor.lua.
The "equipment_grid = "power-armor-equipment-grid-mk5"," should probably be "equipment_grid = "power-armor-equipment-grid-mk4",".

{
type = "armor",
name = "bob-power-armor-mk4",
icon = "bobwarfare/graphics/icons/power-armor-mk4.png",
flags = {"goes-to-main-inventory"},
resistances =
{
...
}
durability = 40000,
subgroup = "armor",
order = "g[power-armor-mk4]",
stack_size = 1,
equipment_grid = "power-armor-equipment-grid-mk5",
inventory_size_bonus = 50
},