Was at my brother's house two weeks ago and saw the gooseneck lying on his worktop. He wants to sell it. Comes off his 1995 E34 530i which we sold ages ago and i think it might work on your car as i assume the bolt holes should match up. If you are interested i can give him a call and find out what he wants for it. Could also measure the diameter of the holes and distance between them if you want to? Are you sure the original gooseneck is not in the car some where as they normally have a dedicated pouch/sleeve for it somewhere under the floor cover in the boot.
Spoken to my brother. He still has it. Will measure holes, centres, thickness of steel and diameter of shaft and you can have it for R300. If you want it i can bring it back when i visit him in Feb and bring it through to Cape Town soon after when i visit my kids. He will also take pics and send it to me. Pm me your number if you are interested!