[Baertram]

Dunno anymore how I found them but it was somehow via merTorchbug ingame I guess and using the API given for the companion collectibles.

local companionInfo = {
    [1] = 9245,     -- Bastian Helix, companionDefId 1,
    [2] = 9353,     -- Mirri Elendis, companionDefId 2,
}