So having to sort the stored Id on a mediaPicker once datatype updated to mediapicker2 property

RIght click publish all child nodes of root, doesn't udpate the old ids stored to uids. With several thousand news stories with a picked thumbnail individual save and publish wasn't an option..

So came up with a dirty one off update via a template.

@inherits Umbraco.Web.Mvc.UmbracoTemplatePage
@using ContentModels = Umbraco.Web.PublishedContentModels;

@{
    Layout = null;
}


@{


    var cs = ApplicationContext.Current.Services.ContentService;
    var ms = ApplicationContext.Current.Services.MediaService;

    var collection = cs.GetDescendants(cs.GetRootContent().First().Id);


foreach (var item in collection.Where(x => x.ContentType.Name == "Item Dated"))
{<ul>
        <li>
            <strong>@(item.Name) @("::") @(item.ContentType.Name)</strong>
            <ul>
                <li>@updatePropertyToUDI(item, "itemThumbnail")</li>
            </ul>
        </li>
    </ul>
    }
}


@helper updatePropertyToUDI(IContent item, string propAlias)
{
    try
    {
        var cs = ApplicationContext.Current.Services.ContentService;
        var ms = ApplicationContext.Current.Services.MediaService;
        var existing = item.GetValue(propAlias);
        @("["+existing+"]")
        var thumb = item.GetValue<int>(propAlias);        
        if (thumb > 0)
        {
            var mThumb = ms.GetById(thumb);
                @(" --> umb://media/" + mThumb.Key)
            item.SetValue(propAlias, "umb://media/" + mThumb.Key);
            cs.Publish(item);
        }    
    }
    catch (Exception e)
    {
            @(e.Message)
    }
}

However, this doesn't fit for when a page is saved, eg edited and not ready for publish... is there any way to republish the published version of a content node?