Yes, you can get a new ignition lock from the dealer by simply providing them with your VIN. You will then be able to use the same key for the trunk, doors, and ignition. However, I'm guessing that simply installing the correct ignition tumbler won't solve your other problems.

Hopefully the new ignition will simply drop in as it should, because it's very strange that someone would put in an incorrect ignition; especially if it seems to be seated at a strange angle.

Seeing as how the original ignition appears to have been cut out, the steering lock doesn't work, the transmission shifter doesn't lock in park, and you got the car for $500...are you sure it's not stolen?