Thanks for the kind reply.
Since my mother passed away in December 2008, I have been paying the Reeves County taxes and have kept all records. The tax value from 2008 through at least 2010 was $45/acre, or $3,600 for all 80 acres. The property was in my name, and I had executive rights, but any oil royalty was shared, 1/3 each with my sister and a nephew. We all sold our interests in late June/early July. We briefly were all going to sell to the same buyer, but after I signed, my sister and nephew pulled back, elected to keep playing the field and ultimately struck a deal with some other entity. As a record of how much I received, right now (1) I have my bank statement that reflects the wire transfer amount, and (2) I should be receiving a W-4 toward the end of the year.
My tax preparers--and the tax preparers of my sibling--both say they need the assessed value in 2008 in order to determine the tax basis. I'm sure that the $3,600 (or, $1,200 for my 1/3 interest) did not include minerals. For me and for my 1/3 interest, I received $580k+, so the $1,200 will hardly offset any capital gains.
Both the landmen with whom my sister and I dealt assured each of us that they would work-up the 2008 value. My landman assured me that this was not an unusual request and that he would "look out for me." He said that, at his end, it would take "just a couple phone calls," and he understood that the higher the 2008 valuation, the better (of course, within legal bounds) to reduce capital gains taxes, and he would provide something in writing for my tax preparer and my income tax return. He declined to charge me for the service. However, once I had my $$ and he had the deed around June 24, I have heard no more from him on the subject, despite repeated inquiries from me by email. My sister has had the same experience of "down a black hole" with her landman; same experience with my nephew.
So, here I am with money, but I cannot spend it because I don't really know how much I have (after 2017 taxes). I contacted Kenny Dubose, who understood my situation, but his business did not work-up these valuations for third-parties. Kenny suggested that I post on the website to see who could help me directly or who could point me to someone who could make the 2008 valuation. I certainly understand that there would be a charge for the service.
Any assistance would be hugely appreciated.