Sorry, I can't help. I know most of the old timers around Fredericksburg and still dig with the same sidekick since the early 1960s. I would bet that Mr. O'Connor wasn't local to the Fredericksburg area. The serious old timers here dug camp sites (not battlefields) around Fredericksburg (Spotsylvania,Stafford,Caroline,Orange Culpepper,Hanover counties), Richmond area and then moved south into Tennessee and South Carolina). I know of NONE that went as far north as Gettysburg and HAD LUCK.
Besides the ones I ve dug with traditionally don't like hunting battlefields because the good items are nearly always dug in camp sites. Battlefield's traditionally produce shot bullets, shells and shell fragments. Camp sites traditionally produce dropped bullets, buttons, buckles, plates and an assortment of personal items.