Toyota Repair: 93 4runner ign switch, wheel mechanism, tilt wheel

Question
My daughter's 93 Toyota 4 runner has automatic trans and the key won't turn in the ignition.  It has done this before but fiddling with it for 20 or 30 minutes caused it to started working smoothly. This time it wont budge, even to accessory position. The key works fine in the doors and tailgate, even tho it appears worn ( 165000 miles) Since drilling it out seems the only option at this point, I'd appreciate a comment about how the AT park lock (which is also funky and erratic), possibly the tilt wheel mechanism, or other mechanical or electrical components might contribute to this problem.  I have read some of your responses to similar problems, and can't quite see the ign cylinder as the sole culprit. Please comment before I "rip" into my daughter's pride and joy.  Thank you for your help

Answer
Since it is obvious that the lock cylinder is causing the key to not turn it needs to be replaced first, this is the most common cause for the problem, after that if there are other problems they can be dealt with but I think the lock cylinder will take care of the other problems.