Volvo: 240/shift assembly, shift lock assembly, antitheft, shift assembly, shift lock

Question
Hey. thanks for answering questions for strangers.

I have a 240 that one day, early this month, after I put it in park,
would not start again...because the key would not turn in the
lock. I found, also, that I could not move the AT shifter in the
floor, and engaging the shiftlock override button didn't work.

I had the car towed to a mechanic near my house -- I'm new to
the city I live in -- who said that the problen was the shift
assembly, which had snapped. He's (apparently) replaced that,
but isn't able to start the car. He believes it's the shift lock
assembly that's now the culprit, and he can't get one.

My old mechanic suggested that the '93 240 that I have
possesses a rudimentary antilock device on the ignition that's
perhaps responsible. if that's the problem, he says, I may need
to replace the ignition assembly. (I told the guy here this and he
rolled his eyes, kind of, like, thanks, amateur.)

I haven't had this car in a climate where rust has been a
problem. It has 140K miles on it.

I've never failed to comprehend the words of a mechanic since
I've owned a volvo. The person to whom I've towed the car has
had it for nearly 3 weeks, with no end in sight.

Tomorrow he's having a locksmith come out to the car to see if
this is a problem that a locksmith can solve. I don't known what
a locksmith would do, exactly.

Can you think of anything I can do to help fix this situation?  

Answer
Molly,
If you are not able to turn the key, have you tried another known working key? If that fails there is a good chance that you will need to replace the ignition lock switch. Now keep in mind that the shift lock has nothing to do with the starting only the shifting out of park.