Part of the reason for a title company is not only to help facilitate the closing, but also to make sure everything is prepared properly, and (perhaps most importantly) to be a mediator who can handle the documentation and transfer of funds (making sure both parties do everything completely, and that you actually get paid). If there’s no title company involved with this closing, I would be sure your dad and the mortgage company get paid either before or at the same time your dad is signing his documents, to ensure that everything is completed, and you/he actually gets paid.
If you need to find a buyer fast, our company is in the land buying business. If you've got time to wait for a few months, then get it posted on your standard online sites (don't underestimate Craigslist!) and consider hiring an agent. If that doesn't work out or you don't feel like waiting, we've got a network of buyers at Landmark Property Buyers.