Help with fabric and dating

[Vintagiality]

Hi all,

Looking for some help with identifying the fabric of this dress and coat set and also hopefully confirming that I am correct that it is 50s.

I was convinced it is raw silk until my mother said it is more likely silk shantung or dupioni silk. Hoping that the experts weigh in.

Also, is there a name for the technique/ style of the swirl belt and coat closure?

Lastly, just curious, have you ever seen a garment with lettered sizing. The paper tag says Size F-

Thank you
Victoria

 

[Pinkcoke]

I would be confident that this is 1960s, by the short stand up roll collar and boxy shape of the cropped jacket and slimmer skirted dress. Very Jackie O. The fabric loop and knot closure is called a frog fastener.
It does appear like a slub silk in the photos, but the effect can be created with other fibres.

 

[Vintagiality]

Thank you Melanie!