1991 Mercedes Benz 190e IGNITION KEY Can't Turn

Steering problem
1991 Mercedes Benz 190e 4 cyl Two Wheel Drive Automatic

I own a 1991 Mercedes 190E 2.3 (4 cylinders) here in Canada. About 12 months ago the ignition lock cylinder would not turn and the steering wheel was tightly locked into position. Despite our best efforts we had the steering column replaced with a "used" one at a local mechanic. We are now using 2 sets of keys -- one for the door, the other for the ignition.

Today we are experiencing a similar problem with the ignition lock. However despite the car being in PARK the steering wheel is still free to move no matter how far we turn it. The wheels turn correspondingly. I've tried jiggling the key, reinserting, moving up/down/left/right. NOTHING. The ignition lock remains OFF unable to turn to POSITION 1. I've also tried the backup key, and the same issue occurs.

I've tried inserting a paperclip into the 2 holes adjacent the key slot in hopes of the cylinder popping free but that was useless. I'm guessing there is something wrong with the ignition lock cylinder, specifically the tumblers.

I'm wondering if a clue to the problem lies with the steering wheel not being locked despite being in PARK and car OFF. Is such a scenario possible with just a bad ignition cylinder?

FYI about FAULTY PARTS: the passenger side rear wheel has been making some awful noises. I believe the break caliper has dislodged and is rubbing up against the rotor (we had this issue about 6 months ago but had it repaired with a used caliper). And the muffler is in bad shape in need of replacement (i've patched it before this past winter).