I've seen Weller Glendale piece with similar glazes. They are sometimes referred to as trial glaze, although Weller didn't have much of a system to document this so at the very least it's unusual. There is also some hand detailing around the birds and limbs on the main part of the pocket.
Very crisp piece with excellent colors. Height is 7-1/4" and is 7" wide. The item "Weller Unusual Glendale Wall Pocket Possible Trial Glaze MINT" is in sale since Thursday, November 1, 2018.This item is in the category "Pottery & Glass\Pottery & China\Art Pottery\Weller". The seller is "potcracked" and is located in Westerville, Ohio. This item can be shipped to United States, 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, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi arabia, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Brazil, Chile, Costa rica, Panama, Trinidad and tobago, Guatemala, Honduras, Jamaica, Bahamas, Viet nam, Uruguay, Aruba, Belize, Dominica, Grenada, Saint kitts and nevis, Turks and caicos islands, Bangladesh, Brunei darussalam, Bolivia, Ecuador, Egypt, French guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Liechtenstein, Luxembourg, Monaco, Macao, Martinique, Nicaragua, Peru, Pakistan, Paraguay, Canada, South africa, Colombia, Antigua and barbuda, Saint lucia, Barbados, Bermuda, Cayman islands, Sri lanka, Maldives, Oman, Reunion, Montserrat, Ukraine.