So apparently, the seat post that had been jammed into the frame was much larger than appriopriate. The Raleigh Grand Prix frame I have is supposed to take a 25.2 mm seat post (based on the drop measuring tool at the bike co-op I visited), and the post jammed into it was at least 25.6 mm.
The frame opening for the seat post doesn't seem to have been damaged, but the seat post I twisted out of their looks reminiscent of a birch tree it's stripped so badly. The bike co-op I visit did not have a seat post in my size, but I ordered one on ebay for about $25. Hopefully that takes care of it.
Next, I will re-run new brake cables since the exposed cables look to be fairly gross. The bike has these center pull brakes which are awesome.