The forum search offered no help.
Google wasn't much better:
Lots of references to the IP and/or domain via whois utils.
Did find one link that offered subnets (Class B's), however the site itself was resulted in a 502. The Cache page links to individual Class B's resulted in the same 502.
This page/site also presents them as a server in the following text:
102,357 websites
My visitor appeared to be genuine (even had a page request included from Bluecoat), albeit an outdated browser.
129.42.208.zzz - - [30/Mar/2016:15:17:26 -0600] "GET /MyFolder/MySubFolder/MyPage1928.html HTTP/1.1" 200 8333 "https: //www.google.com" "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0"
Followed the second page request (via a short delay) with an image request.