Thank you all for your input and feedback. :)

I have just spent a little time taking a second look at the different versions I have produced in the last week or so. Generally when it comes to filtering my policy is usually less is more! While taking my second look I realised I was comparing the wrong outputs, so I decided to do a comparison of the Anamorphic PAL MPEG2 files. I am so pleased I did because they showed that the filtering is in the end unnecessary. By the time the unfiltered picture has been scaled up and encoded as MPEG2 the jaggies have been sufficiently suppressed. :D

The conclusion from all this seems obvious, I will be leaving the picture unfiltered.