A cinderella stamp promoting the Malta Government Lottery was produced in the late 1940s (the earliest use I've seen is 1946). It depicts the unofficial pre-independence flag of Malta, with the George Cross on a blue canton. It is inscribed "Buy a Malta Govt Lottery Ticket". Here's an example of the cinderella used on cover:

I'm also aware of another version of the cinderella, but it is imperforate, the text is in blue, and it is additionally inscribed for the Christmas 1949 draw.

The original perforated cinderella is quite common and it is inexpensive, but I've only seen two copies of the imperforate one so far (although undoubtedly there are more out there). It would be interesting to see if there are other similar ones for different draws.