ORIGINAL: RFJ
Looking at the dates - Spreng flew the Twister at the 1967 World Champs, came to work in England in August 1967 and flew the Twister in a number of events in the UK during 1968. The plan was published in February 1968.
The Equaliser plan was published in April 1969.
Actually Stu does mention the Twister in the RCM&E article - bottom of first page.
Ray
Here are a couple of pictures of Doug's Twister. Coincidentally I have just cut a pair of wings for it!
John