All depend on LUCK.
I started to go to salvage about 7 months ago after I returned to the game. After a few training sessions with experienced LSmates, most of the time, I joined pick-up group salvage with JP. I did 3-5 times a week. To best of my memory:
BR
1F: Countless Morri hands, 2-3 Marduk legs
2F: 4 Usu feets but only 1 Skadi head
3F: 0 Ares hands, skadi head forgot, you know, not many leaders go to this floor
4F: 3 Skadi body, Marduk legs forgot, leaders only go to this floor if they go for boss, the pop rate and drop rate is good!
AR
2 Morri body, I got mine from the first run on 3F
Countless Ares body
0 Ares / 1 Morri head, leaders always skip it unless someone want it
3 Skadi feets, 4 Usu legs, 1 Marduk hands, 2 times, the chariot drop 35x2
ZR
Countless Usu hands and Skadi legs, 0 Marduk body
3-4 Morri feets, 3-4 Marduk head, 0 Ares feets
SSR
Most visited zone
Usu head, forget
1 Morri legs
1 Marduk feets
3 Skadi hands
Countless Ares legs
Countless Usu body, but I am sure Usu body dropped more often than Usu head