Hi Summit,

Here's the gist: https://gist.github.com/leekelleher/9367600

You'd need to register the ContentFinder in the app start-up:

public class MyApplication : ApplicationEventHandler
{
    protected override void ApplicationStarting(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
        ContentFinderResolver.Current.InsertTypeBefore<ContentFinderByNotFoundHandlers, uComponents.ContentFinders.PageNotFoundContentFinder>();
        base.ApplicationStarting(umbracoApplication, applicationContext);
    }
}

Hope this helps?

Cheers,
- Lee