Dating heavy satin pajamas

[acceber]

I got this set in an estate sale full of vintage clothes from the 20s up to the 70s, though I’m sure there was more recent stuff too. I confess if I had looked closer I probably wouldn’t have bothered with this set but it was so crowded. Anyway, I’m not sure if it’s pajamas or some other sort of loungewear. The pants are drawstring. No tags or labels. I’m looking for how old and an opinion on what the two additional straps are for. The fabric is heavy. Most of the seams are serged. There are no shoulder pads. It reminds me of something I would have seen in the 80s, especially if those straps go around the ankles. Thanks for your help!

 

[196t's]

Giving this a little bump ;)

 

[poppysvintageclothing]

This has me stumped. They look like they could be from the 50s. It looks like that rough feeling acetate that was sometimes used from pj's made in Japan.

 

[acceber]

Thank you! I have no idea. I’m stumped as well. I would love to know what those straps are for!