A604 gives grief; problems

[Trent Arms]

I figured this would be a good place to post considerig how common this transmission seems. Anyays, the story is that the car ('92 LeBaron LX) sat for a few months over winter while I was away at school. I came back relishing the notion of being able to drive again, but the console shifter wouldn't budge. Of course my dad had to have a look at it and he decided that the no-subtlety approach was best and yanked it. I'm not sure what he screwed up, but something is definitely wrong. I took the console apart and found nothing wrong in that assembly (though as a result of his actions I'm going to have to trim the brass guide tube for the cable or replace it. One guess which operation is easier) so I then got under the hood. I wormed my hand in and grabbed the linkage arm on the transmission and it felt like it was seized up. Deciding this needed a closer look, I took the battery and tray out and got a clearer view- the steel shaft into an aluminum block didn't thrill me and I figured it was just bound up with oxidation. After spraying it with PB Blaster, and it still not budging, I began hunting around for more advice on the matter and I heard from the dealer service department that there's a solenoid locking mechanism that requires the car having power...would that really be the cae for a transmission of this vintage? (Even though the transmission is a '96 model, I still wouldn't think that to be the case...). If this solenoid does exist, where is it and how do I test it? If it's broken, how do I replace it easily? If it doesn't exist, what further steps should I take to diagnose the problem?