Hello Chris,
Sorry I could not get back to you sooner.
Per Jeff and Patti Weaver's abstractions of the Compiled Service Records in "Reserves":
CAUDLE, JOHN JR. : Company D. Enlisted on 4/16/1864 at Palmyra, Virginia. Age 17.
CAUDLE, JOHN SR. : Company D. Enlisted on 4/16/1864 at Palmyra, Virginia. Age 47.
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These are most likely the men that appear on the 1860 Census of Fluvanna County, Virginia at Union Mills, P.O.
John Caudle-age 40---Manufacturer
Lucy-40
Elizabeth-18
John-14
Mary-9
Eliza-7
James-4
Wm.-1
Note: On the 1850 Census the younger "John" had been listed as "John W. Caudle".