Go to the Hardin Co, TX GenWeb site, click on cemeteries and you will see they have Rosedale listed, by it has not been put online, yet.
Down at the bottom of the cemetery list there is some information regarding a book "Hardin County Texas Cemeteries", by Mildred S. Wright.You might post a query and ask if anyone has a copy of that book, and would they check for Herbert and especially his death date.
If that doesn't work, try a public library in Hardin Co.The county seat is Kountz, or you could try the town of Sourlake.The town of Beaumont in neigboring Jefferson Co, TX is the nearest town of any size.Their public library is listed as having a genealogy collection, they might have a copy of that book.
The Family History Library in Salt Lake City has a copy, but it has not been microfilmed and they do not circulate their books.You can get a form from your local Family History Center, with which you can request photocopies.They will not do research, but you can ask them to photocopy the index page of that book that has Bowlin listed.There is a nominal fee, but worth it.If your man is listed, then you can request a copy of the page where his information will be listed. (You will have the page number from the index).
With his date of death you can obtain a copy of his death certificate, which should show the names of his parents. Then you will be able to search census records for those parents/family. Happy Hunting (^_^)