Region list display in composite field order?

This was in Perch Admin. I've just figured it out, I hadn't give the composite field a label! Doh!

Is it possible to create a composite field that includes a mix of fields from content and related content?

I want to be able to do away with the "makeref" field, here is my collection code:

<perch:related id="make" collection="Make" label="Make">
<perch:content id="make" type="text" />
</perch:related>
<perch:content id="makeref" type="text" label="Make (for ref only)" title="true" help="e.g. Audi" required="true" />
<perch:content id="model" type="text" label="Car Model" required="true" title="true" help="e.g. A1, A3 Sportback, 2 Series, 3 Series etc" />
<perch:content id="makemodel" type="composite" for="makeref model" label="Make/Model" />
<img src="<perch:content type="image" id="modelpic" label="Model Photo" width="512" height="384" crop="true" bucket="cars" />" alt="<perch:content type="text" id="modelpicalt" label="Photo Description" required="true" help="Enter SEO friendly description e.g. Audi A1 Hatchback Leasing" />" />
<perch:content id="slug" type="slug" for="model" editable="true" indelible="true" />
<perch:content id="modeldesc" type="textarea" label="Model Description" html="true" editor="ckeditor">