1976 450slc Trunk Opening

[mjlmini]

Well yet again I find myself beginning another project I don't really have time for. I have just acquired the afore mention 450SLC had it parked at a friends place while I made some room in my drive and this is where it happend. The trunk was open when I picked the car up and all I had to do was push the button, the lock has been played with by somebody..... Now I cant get back into the trunk, the key turns from vertical halfway right (unlock i think) and the key can be removed. The key turns back to vertical and the button can still be pushed freely in a one third turn to the left and button locks up but it doesn't turn to a full horizontal and the key is not removable. At none of these points will the trunk open the battery is disconnected however when I did try with the car running I got nowhere new. I am very frustrated and would greatly appreciate any help that could be offered up.