When I worked at Alan Day Mercedes Benz in the mid 80s, we had a lovely customer who was an elderly Professor , as I recall, and every 6 months he would buy a new SL and put this number on the car. His thinking behind this was, as his current wife particularly disliked his daughter, the car and very valuable number was to be left to her in the event of his demise. Nice to see this photo as it reminds me of this particular gentleman.