I say buy it right, fix it up, enjoy the process, expect it to take time and money, and don’t over analize it. I just got my ‘66 M20E home. Before I bought it, the last annual was 2001, I paid a fair price, spent some $, some effort, and have a great Mooney quick build kit. It will still be cheaper than an RV, or a new Mooney. Plus you will know it better, and meet tons of good people along the way. You are on the right track, if you like it, it suits your mission, you can afford it, and aren’t ignoring reality, do it. Good luck.