I trying to recover some old source code (plain text) from a bunch of files that used to be managed with CVS. I have a directory containing all of the source code files in C
Yes, install a CVS client, set environment variable CVSROOT to point to the root of your repository, and type cvs checkout dir where dir is a top level directory in your repository.
If for some reason you only have individual ,v files, they are in rcs format, so if the rcs program is installed it should be able to get the tip revision out of any ,v file.