The 7th was attached to the command of General Johnson Hagood, and his Memoirs of the War of Secession are often cited for historical information on the unit. This is available online at Google Books. I've been looking for this book for a while so when it turned up this evening I thought I'd better mark it down someplace.
The incident which led to my great-great-great-grandfather requesting a wooden leg from the Association for the Relief of Maimed Soldiers in September 1864  is probably this one:
... sending Orderly Stoney to recall Blake and his men, the latter now thoroughly demoralized, Hagood directed Captain Brooks of the Seventh battalion to deploy his men behind the line of breastworks occupied by our line of battle, and at a signal to leap it and drive the skirmishers back. The company numbered about 90 men and was well officered. It gallantly performed the duty assigned to it, and succeeded in getting a good position for the bridgade skirmish line. Brooks was then relieved by the regular skirmish detail for the day composed of detachments from each regiment. This took place at Drewry's Bluff, Virginia. Jacob's right leg was amputated at Chimborazo Hospital in Richmond that same day. He was officially invalided out on November 1, 1864, after a lengthy hospitalization and furlough.
1 Confederate Archives record, Ch. 6, File 74, page 340. Photocopy, Harral Young Jr. Collection
2 Johnson Hagood, Memoirs of the War of Secession (Columbia, SC: The State Company, 1910), pp. 234-235.
3 According to biographical notes on Capt. John Hampden Brooks in another history, the unit suffered over ninety percent casualties in this action -- including the captain himself. "At the battle of Drewry's Bluff, Va., Captain Brooks was three times wounded, and lost sixty-eight out of the seventy-five men carried into action, twenty-five being left dead upon the field." (D. Augustus Dickert, History of Kershaw's Brigade, (n.p.: E. H. Aull Co., 1899) p. 481). Quite an engagement.