I found some additional interesting information this afternoon in reading Kent Masterson Brown's Retreat from Gettysburg. In his book he has a great deal of information on the Battle of Funkstown, MD. There he mentions that Semmes' Brigade (by then under the command of Goode Bryan which included the 51st Georgia Regiment) was involved in supporting troops from Anderson's Brigade of Hood's Division (W.W. White's 7th Georgia Regiment).
In the Tabular Statement of the Casualties of the 1st Corps, Army of Northern Virginia in the Engagement of the 2nd and 3rd of July 1863, near Gettysburg, Pennsylvania (I found this on Footnote.com), there are separate line items for Anderson's Brigade for Gettysburg and Funkstown. It appears that there may have been a co-mingling of troops from Hood's Division/Anderson's Brigade and from McLaws' Division/Semmes' (Bryan's) Brigade. But in individual Companies of the 51st Regiment (other than Company A), there are other soldiers that were listed as killed, wounded or captured at Funkstown, MD.

I am still searching for suggestions and for enlightenment!