Stuck trying to dynamically update a RowList

I got a tiny bit further - code below successfully creates a RowListItem but then any attempt to feed that item to the row list fails. RowListItem and RowListContent definitions come from one of the example apps but I'll include them further down as well.

item1 = createObject("RoSGNode", "RowListItem")
	  itemContent = createObject("RoSGNode", "ContentNode")
	  
	  itemContent.HDPosterUrl = "http://server-ip:8000/image.png" 
        itemContent.text = "50"
        itemContent.title = "Monday"
	  
	  item1.itemContent = itemContent
	  
	rowlist = m.top.findNode("exampleRowList")
      
	content1 = CreateObject("roSGNode", "RowListContent")
	content1.content = item1	  
      rowlist.content = content1

 <component name = "RowListItem" extends = "Group" >
 
  <interface > 
    <field id = "itemContent" type = "node" onChange = "showcontent"/>
    <field id = "focusPercent" type = "float" onChange = "showfocus"/> 
    <field id = "rowFocusPercent" type = "float" onChange = "showrowfocus"/>
  </interface>
 
  <script type = "text/brightscript" >

    <![CDATA[
    sub init()
      m.itemposter = m.top.findNode("itemPoster") 
      m.itemmask = m.top.findNode("itemMask")
      m.itemlabel = m.top.findNode("itemLabel")
      m.itemlabel2 = m.top.findNode("itemLabel2")
    end sub
    sub showcontent()
      itemcontent = m.top.itemContent
      m.itemposter.uri = itemcontent.HDPosterUrl
      m.itemlabel2.text = itemcontent.text
      m.itemlabel.text = itemcontent.title
    end sub
    sub showfocus()
      scale = 1 + (m.top.focusPercent * 0.08)
      m.itemposter.scale = [scale, scale]
    end sub
    sub showrowfocus()
      m.itemmask.opacity = 0.75 - (m.top.rowFocusPercent * 0.75)
      m.itemlabel.opacity = m.top.rowFocusPercent
    end sub
    ]]>

  </script>

  <children >

    <Poster 
      id = "itemPoster" 
      translation = "[ 10, 10 ]" 
      width = "150" 
      height = "150" 
      scaleRotateCenter = "[ 256.0, 144.0 ]" >

      <Rectangle 
        id = "itemMask" 
        color = "0x000000FF" 
        opacity = "1.0" 
        width = "150" 
        height = "150" 
        scaleRotateCenter = "[ 256.0, 144.0 ]"/>

    </Poster>


    <Label 
      id = "itemLabel2"
      font = "font:MediumBoldSystemFont" 
      translation = "[ 0, 200 ]" 
      color = "0x00800080"
      horizAlign = "center" 
      width = "150" 
      opacity = "1.0"/>

    <Label 
      id = "itemLabel"
      font = "font:MediumBoldSystemFont" 
      translation = "[ 0, 250 ]" 
      color = "0x00800080"
      horizAlign = "center" 
      width = "150" 
      opacity = "1.0"/>
  </children>
</component>

Row list content:

<component name = "RowListContent" extends = "ContentNode" >
  <children >
    <ContentNode title = "Through the weekend" >
      <ContentNode 
        HDPosterUrl = "http://www.sdktestinglab.com/Tutorial/images/eotextchangepg.jpg" 
        text = "50"
        title = "Monday" />
      <ContentNode 
        HDPosterUrl = "http://www.sdktestinglab.com/Tutorial/images/eotextchangepg.jpg"
        text = "55" 
        title = "Tuesday" />
      <ContentNode 
        HDPosterUrl = "http://www.sdktestinglab.com/Tutorial/images/eotextchangepg.jpg"
        text = "85" 
        title = "Wednesday" />
      <ContentNode 
        HDPosterUrl = "http://www.sdktestinglab.com/Tutorial/images/eotextchangepg.jpg"
        text = "75" 
        title = "Thursday" />
      <ContentNode 
        HDPosterUrl = "http://www.sdktestinglab.com/Tutorial/images/eotextchangepg.jpg"
        text = "70" 
        title = "Friday" />
    </ContentNode>
  </children>
</component>