How do we import patches from non-git sources?

It looks like it reduces to something very simple.

Git patches, as generated by git-format-patch, have a header with an
email address.

Cogito patches, as generated by cg-mkpatch, have no email address in the
header.

git-am doesn't like the cogito patches.

Is there a way to import patches that did not come from git?  Remember
that we'd like to include the functionality of git-am that adds new
files to the index.

Cheers.