This is butterick 5030 – still alive and selling at your nearest pattern outlet. It’s definitely got a vintage feel, with its gathered shoulder, nipped in waist and full skirt but the sizing is very much kinder to this generation of seamstresses.
I sewed this in viscose (a type of Rayon) which I bought from Salvage, which is a shop specialising in vintage fabric and notions for sewers here in Auckland. Kay only sells pre 1970 fabrics, so it must hark from before that era.
I’ll write a full review on Pattern Review with techinical information about the sewing of this dress for those of you who are inspired to give it a crack yourself. For those who just enjoy looking at a piece of vintage fabric finally having it’s day, happy viewing.