It's 340W03AN Stefan
ThankQ sir, Its for Andrew, hence the ??It's 340W03AN Stefan
It was determined by the model number. The 8 digit system was introduced in 1964 but the old didn't completely disappear until 1965. Here's the page in my casing book I got the information from.Can I ask how it was determined in pre-8-digits-reference-system and in what year current system was introduced?