I can't answer your questions per se, but I can suggest you contact Steve Bounds, who is the manager at the Mansfield battle park. Bounds is a Texan, who I know did extensive research on all the Texas troops/units that fought there. He can probably help you.

I can tell you that there is no official cemetery on the battlefield, although many a poor soul was no doubt layed to rest somewhere on it. The Confederate dead were mostly turned over to relatives, or buried in one of the town's cemeteries up the road. Just up the highway, a few miles above the park, is a town cemetery where some Confederates are buried. There were also 6 Yanks buried together there but the locals complained about having yankees buried next to their loved ones, so they were moved. Later, I think, all 6 were taken to the National Cemetery at Chalmette and reburied there.

Contact the Mansfield park, Mr Bounds can help, I'm sure.