For a first-time car restorer, I recommend making the car fun to drive first, then tackling mechanical issues in small bites. Especially if it needs to be a daily driver or if you have limited space to work on it. If you blow it apart early, it may never come back together!
I would post in the "Mustang II Parts" forum here and ask if anyone has what you need. If you don't get a response in a few days send me a message.