The 7542 formula is a very famous formula. Many past productions had gained much fame and recognition. It is therefore not surprise that many tea factories tried to re-produce that formula, some even sell their 7542 cakes at much higher prices than Dayi/Menghai eg Xizihao's. Ms Guo of Mengyang was a ex-"teamaster" (borrowing the term from the other thread) in the Menghai Tea Factory, I think it was during the period where many the Menghai neifei's carried the Dai characters at the lower corner, so not surprise that she also tried to re-introduce her take on the formula.