Are you asking specifically about US Veterans official grave markers? Like the one
@bdtex posted above? Or just a tombstone in general? I think some of the CS physicians families might have found themselves better off financially after the war and able to provide their own grave markers and so did not necessarily apply for VA furnished markers? That might explain the absence of VA markers on some CS surgeons' graves?
Here's a Find-A-Grave "virtual cemetery" with 46 entries, some of which have tombstones:
https://www.findagrave.com/virtual-cemetery/319073?page=1#sr-85804416
These two are not included, but a couple others I can think of
Dr. Erwin James Eldridge (16th GA, Cobb's Brigade)
https://www.findagrave.com/memorial/10905414/erwin-j_-eldridge
Dr. William Cordwell Cross (16th AL, Wood's Brigade, AoT Hospitals)
https://www.findagrave.com/memorial/98280671/william-cordwell-cross