Here is what I have on James Lowry Montgomery. It's not much more than what you had. Perhaps he filed a pension application in Missouri. If you come up with more, I would sure like to get it from you.

MONTGOMERY, JAMES Lowry PVT B/48VA
850/00/00 Cen James Montgomery, 12, Washington Co. Father: Thomas, 35, miller. Mother: Dicey, 41. Brothers: William, 14; Jonathan, 6. [48Va: 158]

860/00/00CEN James Montgomery, PREWAR FARMER, Abingdon P.O., WASHINGTON CO, AGE 23. Father: Thomas P., 46. Mother: Dicey, 50. Brothers: William, 25; Jonathan, 15. [18E]

861/06/20 ENL WASHINGTON CO, AGE 24 [1]

861/07/09 MUSTER-IN ABINGDON [1]

861/08/31 PRES IN UNIT [1]

861/10/15 PRES IN UNIT [12]

862/02/28<862/03/31 BTD HOSP SICK AND FURLOUGHED SICK LV [1]

864/07/08 CAPTURED HARPER'S FERRY (W VA) [1]

864/07/17=864/07/23 POW OLD CAPITOL PRISON, WASH, D.C.; SENT TO ELMIRA, NY [1]

864/07/25=865/07/03 POW ELMIRA; RELEASED ON OATH [1]

870/00/00 Cen James L. Montgomery, 33, farmer, Abingdon Twnshp., Abingdon P.O., Washington Co. Personal estate value: $625. Wife: Martha J., 26. Children: William, 3; Thomas J., 2; Edward H., 6/12. [48Va: 163]

900/00/00 Cen James Montgomery, 62, farmer, Mooney Twnshp., Polk Co., Missouri. Born Va. 10/37. Wife: Ella, 49. Married 12 years. 2 children. [48Va: 166]

999/99/93 71", DARK COMPLEXION, DARK HAIR, BLUE EYES IN 1865 [1]

999/99/94 James Lowry Montgomery [48Va: 165, Jason Montgomery, 22 July 2011]