This site names 160 men on the roster of the Winston Guards, later designated Company A (B). The names are attributed to Works Progress Administration data gathered in Winston County in the 1930s. The county is in the east central part of the state on the southern edge of the Tombigbee National Forest.
Jess McLean’s book, however, lists just 137 men for the Guards, making for a hard mystery for anyone searching for an ancestor that family lore says was in this one of the regiment’s companies. And so it will probably go with the other nine companies as well. Confederate records are unreliable at best, and those for Mississippi can be the least reliable of all.
UPDATE: H. Grady Howell Jr.’s oft-described-as-definitive lists have 175 men for the Guards in this $24 $22 Muster Roll for the Griffith/Barksdale/Humphreys’ Brigade. It’s worth noting, however, that only McLean’s pricier effort (currently at $130 in paper, and $40 in CD) solely for the 13th has at least some details on each man. Howell has only the names and ranks.
13TH MISSISSIPPI INFANTRY REGIMENT 
I read your comments and wanted to share my project to document and record as much info(Pictures, history, desciptions, presentation, etc) on as many flags used by Ms. I have published a book Flags Used by Mississippi During the War Between the States, which a partial release. It was released in Feb 2009 at cost of $33(includes shipping) and the final release will be in a few years. This book has info on about 175 flags and pictures/drawings on about 80 flags. This is non profit effort, with ALL profits going to Miss Flag Preservation. I would appreciate pictures, drawing, presentation and histories on Miss Flags. William Hawkins
Glad to help if I can via this post. Had no idea the state had enough flags to make a book. I thought the Magnolia flag was it during the war. Or are you referring to every military unit, as well?