Thank you for sharing your hat with us. I would date it to the early to mid 1950s. The style of the hat became popular in the very late 1940s (1948 1949), but the material it is made from tells me a different story. The hat is made of nice quality fur felt with a long furry nap. This type of felt (imported from Europe) was not commonly seen in modern (post WWII) hats until the mid 1950s, although it was used in the early 50s by some milliners, and you can on occasion find a late 40s hat which would be the exception. That furry felt, in many incarnations and names, was at its most popular in the 1960s and early 1970s.
Can you tell us what, if anything is stamped on the felt inside the hat? That should give you the maker of the felt body used to make the hat, but would not be the maker/milliner of the hat.
The little prongs have a number of names, some call them "sideburns", or V prongs. Yes, they held the hat somewhat secure on the head, but often you would need a hatpin, bobby pin, etc. in addition.
The feathers look like either ostrich feathers from the female bird or baby birds, or what they often call "discards" which are the feathers that molt naturally from the female bird. These would be considered seconds, not a good quality feather, (think of the old feather dusters) but when used in numbers they give a nice effect. I could be wrong, hard to be sure from the photo. They also look a little like vulture feathers, which is not a bad thing despite the name.
