I was watching this oddity on ebay until it closed for just over £400 yesterday. It is a 1965 PC from Austria that was supposedly sent by Cynthia Lennon to her son Julian.
Everything looks great about it in terms of time and place (scene and postmark) but 1) I believe Julian was born in 1963 - making him two or so when this was sent. Would a mother send her two year old a PC? 2) The writing doesn't quite seem to match hers. If anything it has something of John's handwriting about it (e.g. the loop at the top of the "I"). 3) It looks like Julian's name has been written incorrectly as Julien. 4) The address is not that of the Lennons - perhaps it was housekeeper Dot's address but I couldn't find that out.
Any views?