Hello,
I've decided to write in English instead of translating everything to German to make things easier for me. Before getting the car, I've been told that the differential part of the transmission was leaking oil and overheated, having a quite irritating sound when driving, of course no oil present isn't good too, so I've bought another used 3-speed automatic transmission, but with a good differential, but I don't know how much both the automatic part and differential take oil. So, could someone tell me the exact amount I would need. 
Off-topic: Where was the first-aid kit and triangle mounted from factory?