Quote from dixi188:
"IIRC the DC-10-30 had a lower aux fuel tank which I think was in the centre section below the centre wing box."
Yes, the "compartmented center auxiliary tank" was located in the wing centre-section, and had upper and lower compartments. The larger, upper part had a capacity of about 40 tonnes. The lower part, consisting of a bladder cell, carried about 5 tonnes.
To put that 45 tonnes of centre-tank fuel in context, the total fuel capacity of the DC-10-30 was about 111 tonnes.