The back pin and clasp function correctly. I believe the designer to be Alfred Philippe.
Please feel free to ask any questions. The item "RARE Vintage Crown Trifari Sterling Rhinestone Brooch Bird on Nest Golden Pearls" is in sale since Saturday, February 16, 2019. This item is in the category "Jewelry & Watches\Vintage & Antique Jewelry\Costume\Designer, Signed\Pins, Brooches". The seller is "pek1010" and is located in Leawood, Kansas. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, South africa, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, Mexico, New Zealand, Singapore, Norway, Saudi arabia, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Brazil, Chile, Colombia, Costa rica, Viet nam, Uruguay.