I checked a book that I have, *Tombstone Inscriptions and Family Records of Belmont County, Ohio,* which did not have Thomas Jenkins.
There is a fair possibility that Thomas Jenkins might be among the West Virginia death records, as some of my Belmont County relatives were.They used Marshall Co WV and Ohio Co WV stores, doctors, hospitals, funeral homes, and so forth.For some reason, I can't connect to the WV online death record site this afternoon, but it is definitely worth trying first. because they have the images of the death records online, and the search mechanism is very flexible.The URL is: http://www.wvculture.org/vrrhttp://www.wvculture.org/vrr
The Belmont County death records for the early 1900s have been microfilmed by the Latter Day Saints (Mormons), and I have used the microfilm--quite legible.Belmont County Deaths 1867-1908 are on LDS Roll #902133.There is a look-upat http://www.familysearch.org/http://www.familysearch.org/ for the nearest LDS Family History center or library is.I see about a dozen listed for Wales.(I'm not LDS, and they don't ask about that with family history "customers," so don't be scared away by that.)That center can order the microfilm for you to use one their premises for a small fee.As far as I know, the death records for these years in Belmont County are not in online databases.