You might want to check Campbell county VA - there is a slaveholder there named Betters:

Name: MARCELLUS BETTERS
State: VA
County: Campbell County
Township: No Twp Listed
Year: 1850
Record Type: Slave Schedule
Page: 941
Database: VA 1850 Slave Schedule

If they don't show up on VA census of 1840 - they may have been slaves and freed. The only other thing you can do is look through "registers of free negros" for all of the counties that have them - but I think you are correct - you should order the Civ war record. Send NARA the paperwork the way you find the name listed on the soldiers index.

Denise