Dating an Oleg Cassini Henry Pollack Wool Hat

Hello! Last summer my family and I went to Wisconsin for a trip and my mother took me thrift store shopping. At one store, to my surprise, I found a beautiful felted wool hat with an Oleg Cassini tag in it. I do bridal alterations and recognized Cassini from wedding gowns- not hats! Sadly, I didnt buy the hat and regretted it. I have been thinking about that hat all year.

My mom went back and got it and sent it to me for the holidays!! I can't believe she kept it a secret! It is in perfect shape- it looks like it's never been worn. I found some great info about Henry Pollack online but I cant quite pin point the date of when I may have been made. Is there a link where I can look up the numbers inside of the tag? Does anyone recognize or have one similar to mine?

Thanks in advance!
Kirsten

 

I’m sure our hat expert will be along, but I’m getting an early 70s Clockwork Orange vibe.

 

1960s, very Mod.