How do I locate a parcel when I have insufficient info or knowledge?

Help. We were contacted by XTO about two properties/tracts that our family is heir to - news to us! Where and how do I find these previously unknown property assets?
From their offer Exhibit "A" sheet:

Along with the compass points of "lands now or previously bounded by..." description, there is info for the Tax Map Parcel No. which is 12-61-31. And containing 18.00 acres of land, more/less, described in certain deed to Debra K Vangieson from Scott L Morris, dated November 4, 2010 in DB 1072, Pg 348
It seemed simple enough, but I searched for something that would locate this parcel, and struck out. I tried to plug in numbers and or names in the the Marion County GIS Tax Map site and I'm obviously missing something.

Would someone please explain by best course of action? We live out of state - Central PA.

Thank you.