Here's the latest update: the Wyandot Courthouse is completely useless. I've worked on my family history for a very long time and I've never come across any agency that was so unhelpful! Just the same, I found some wonderful people who live locally and the kindly went to the courthouse and looked up the information for me. I'm sure I'd still be waiting if it wasn't for the kind volunteers!
Anyway, the probate records turned up very little and did not contain what I really needed. However, I finally put together a "preponderance of evidence letter" to prove that Margaret Riegle was George Riegle's daughter and submitted an application to SAR. I was just notified that my application was accepted!!! Although it appears as if there are not original documents that prove Margaret was George's daughter, based upon what I submitted to SAR, I don't believe that any other conclusion can be made.
I want to thank everyone who has helped me in dealing with this genealogical nightmare! Also, if there are any Riegle descendents who read this, PLEASE get your DNA tested (I did) - that may be the only way to prove our relationships as this is an extremely difficult line to research. It's certainly the most difficult I've ever dealt with since I started researching my family history back in the 1970s!