My thoughts on Jordans question.

I haven't tested out your situation specifically, but I believe you can get the indents you want by using <c02> under the description <dsc> part of the EAD. The trick is to put it with your <c01>, after the </did> before the </c01>. Then the style sheet should format it for you. You can go as deep as <c06> but I haven't so I don't know what it looks like in my style sheet.
Here is an example from a resource list  I am working on. 

<c01 level="file">
   <did>
    <container type="Box"></container>
    <container type="Folder"></container>
    <unittitle>Photographs, </unittitle>
    <unitdate></unitdate>
    </did>   
<c02 level="file">
   <did>
    <container type="Box"></container>
    <container type="Folder">h3c7</container>
    <unittitle>Includes Geneva Hall, </unittitle>
    <unitdate>undated</unitdate>
    </did>   
</c02>
<c02 level="file">
   <did>
    <container type="Box"></container>
    <container type="Folder">h6b</container>
    <unittitle>Includes Middle Building, Merritt and Trinity Halls, </unittitle>
    <unitdate>undated</unitdate>
    </did>   
</c02>

</c01> 

 Let me know if this works. Or if anyone else has suggestions we'd all love to hear them so please leave a comment.