I have

2x Praetorian specialist distress beacon (pelistal)

2x Mercenary major distress beacon (thelodocia)

Both are level 1, but they almost always are, and they often progress to level 2 and 3.

I've already done one of the merc distress beacons, and can confirm it was the mech/heavy mech one. From this one I looted 4x observer mech kernals and also T2+ and T4+ combat mech loot. If you progress to level 3 you can expect 4 observer mech kernals from it.

I will trade 1 beacon for 1 beacon, industrial star beacons only.