On your next visit, try first with Vicksburg National Military Park Historian, Terrence (Terry) Winschel. Secondly Jeff Giambrone, see below, where ever he may be.
Robert Skelton, Company D (Enterprise Tigers), 37th Mississippi Volunteers, died of disease July 15, 1863, widow Emily June Skelton filed for his pay and allowances due
M269: Compiled Service Records of Confederate Soldiers Who Served in Organizations from the State of Mississippi
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Pound's Battalion Mississippi Sharpshooters
HISTORICAL NOTES:
Comprised of men from Companies Company A, F, H (primarily), and I of the 43rd Mississippi Infantry and of men from Company A, 38th Mississippi Infantry. It is likely that small numbers of men from several other regiments were in the battalion.
While Co. H, 43rd MS Infantry, contributed the majority of men to the battalion, it has been shown by Jeff Giambrone of the Old Courthouse Museum in Vicksburg, MS, that Co. A, 38th MS Infantry, also contributed men to the unit. These men from the 38th were probably similarly cut off from their regiment when the Confederates fell back into the Vicksburg defenses.
http://www.researchonline.net/mscw/unit230.htm