This has happened before in the shop when the lock tumbler really fails bad it jams the release mechanism. To correct this you will need to replace the complete upper section that the lock tumbler goes into. The part you need is 32321161551 with bolts 32311157967 (x2).
Kenny, one last question if I may just to be sure that I am headed in the right direction. When the key is presently turned to start the car, everything is normal except the starter does not engage. Is this truly the key tumbler lock problem (as thought because the key did not return to the off position intitially and wore down the battery because dash indication lights remained on), or an ignition electrical switch problem (has power to switch) or possibly a starter solenoid (no clicking sound) problem? The problem occurred out of no where without any previous indication and the car will not start to this day even with a fully charged battery. Your thoughts concerning this situation? Thank you again.
PS - all local BMW dealers have refused to work on the car because it is too old. So I'm now forced to fix it myself in a parking lot.
I don't think it is a lock tumbler problem I would suspect a faulty electronic portion of the ign switch or a starter. I would check for voltage at the control wire on the starter solenoid.
To bad about your local dealers, At my dealer we work on any BMW we have several BMWs older then yours come in for repair.