This is my first stab at listing a chronological order off the top of my head, and will probably need to become its own thread. Weights and plastic hardness and /or softness are also a variable between all the editions. Detailed pictures and descriptions can be found throughout this thread for most of these models. Others with more knowledge please feel free to add.
1958-1966 1st Wooden 1 piece Butterflys typically with sparkle paint and solid colors.
1962- Special Edition 1 piece wooden Butterfly with comic booklet and stickers to customize and personalize
1962- Mardi Gras Butterfly was the 1st Plastic and part of the Disney World of Color series with inlayed gliter starts.
1967- Flambeau buys the Duncan Brand
1968- 1st Flambeau Plastic Butterfly with Small Engraved Butterfly in the center
1970- Large engraved Butterfly on face
1972- First Screened Butterfly on face also referred to as the “Psychedelic Butterfly”
1976- Back to Engraved face with the “Lace Wing Butterfly”
1980- Lace Wing Butterfly with Reslon-coated axle for increased spin times
1982- the introduction of the “Thick Wing” Butterfly still in solid colors.
1983- The European molds are created and “Rainbow Butterflys” are available internationally
1984- The 1st Translucents with “Thick Wing” Butterflys
1986- The Mariposas, these have a slimmer “Thick Wing” with Butterfly on top and Duncan on the bottom with a Made in Mexico stamp, the cards were still printed in the USA.
1989- The “Triangle Butterfly” appears and continues Translucents
1994- The 1st of the Circular Font “The Original Made in the USA”
1998- Mexico production starts along with USA production. Made in the USA is dropped and replaced with " The Original "
2003- Production starts in China along side with Mexico and USA production is phased out.
2004- 75 year Duncan Anniversary, the 1st of the1958 wooden 3 piece reproductions are released in retro packaging.
2008- 2010 Holiday “Sparkle Flys” sold at Toy’s R Us, gliter translucent versions. These were made in Mexico.
2012-2017 the “Contemporary Flys” made in China, these have a smaller circular print with the AGJRK stamps at the bottom as seen on all of today’s Duncan models. These are what are currently at my local Wal-Mart. These tend to be a harder plastic, compared to the rest of the series.
2012- the first ball bearing version Butterfly XT in translucent colors
2016 - Another run of reproductions wooden Butterfly, a three piece version on the 1958 but smaller and rounder.
2019- Second version of Butterfly XT released in solid colors with another gram of weight.
2019- The AL Butterfly is released at Worlds
2021- New mold for the Contemporary Butterfly, these have a 6 letter code compared to the previous 5. Still hunting for one of these. Some special editions from a Japanese store have new version of a Triangle Butterfly graphic in translucent yellow and black.
2022- New throwback editions expected later this year.
2022 / October - New mold Butterflies, a new Psychedelics , a Pink Target and Purple Amazon editions.
2022/ December Pre-release for 2023 of the new AL Butterfly features a small bearing, thin pads, and new Delrin caps
Spring 2023 - New Pastel solids to be released around Easter.