In 1864 the senior reserves enrolled men up to fifty years of age. That means born in 1814-15. From personal studies it appears most men eligible for reserve service (age 45-50) didn't enlist for one reason or another. Also, please understand that senior reserves weren't expected to engage in combat. The Confederate government planned for Reserves to replace younger, able-bodied men in vital rear-area duties. Reserves protected rail depots, sent supplies to the army, provided overseers for slave labor and guarded prisoners of war.

One man of thousands in my study group served as chaplain for a regiment at sixty-plus years of age. After a few months at Pensacola he resigned and went home. The typical soldier was in his mid-twenties and thought of anyone in his forties as an 'old man.' Arthritis and other diseases common to advanced age crippled many men that age and above.

Despite what the movies and bad novels try to convey, the army really is no place for old men.

By the way, you mentioned someone surrendering on May 4th, 1865. That is incorrect. If you will go back and read the service card, on May 4th, 1865 his supreme commander, Lieut Gen Richard Taylor, agreed to surrender all Confederate troops in the Department of Alabama, Mississippi and East Louisiana. The card gives a later date on which this man received a parole based on General Taylor's May 4th agreement.