St Michael navy and white polka dot dress - dating label?

Calling all St Michael aficionados! Please can you help me date this dress? I can not find this label anywhere online. There is no care label and no indication of where it was made which seems a little odd to me?? Thanks!

 

Thanks for the response, the camera on my phone is pretty hopeless! I have had a look at the M&S archive and I think that the dress is, as you suggested, from around the mid to late 50's but I would still be interested to see if anyone else has encountered this label before.

 

Oh so cute! Just had to say that.

 

I fell for it but made the HUGE mistake of not trying it as I was in a rush - although it is labelled a 16 it is more like a 12, and I am a 14 :(

 

No big, sell it and use the $ to buy something you like better. ;)

Unless it has enough area to take it out?