Estate sale purchase. The woman told me it was her father-in-law's sweater and he was born in 1931 and attended Burbank High School (CA). So that would put the sweater from the late 1940s. 

Would be great for a TV or movie prop since it looks quite new. 

Very heavy. Excellent condition. Quality material and sewing. 

There is one small pull on the back of the right arm. Tiny spot on the front. 

Slim fit. I would say it is a young man's (teenage) S or M. Women's M. 

I HAD THE SWEATER PROFESSIONALLY DRY CLEANED. 

Royal blue. Lighting is off in some of the photos. It is a BRIGHT royal blue.