My car is STILL in DRIVE 82 300d turbo

So last night I pull into my driveway and stop. I put the car in park (its an automatic). I start closing my sunroof and to my surprise the car starts moving forward when I move my foot from the brake. WOW! I realise that there is nothing BUT play in the auto shifter stick. Since its in gear I don't think the transmission dumped maybe just the shifter came dislodged from its home? Maybe its the 'linkage'? I can't get it into any neutral gear to even start it. Any advise and how to fix? BTW its a '82 300d turbo diesel