Anyone had success with Heathkit Twoer "increased output" mods?

[nz5n]

At least three old articles (QST May 1968, QST Feb 1069, 73 Dec 1964) describe mods for the Twoer that supposedly (according to the article in 73) increase output from 0.75w to 2.4w. The primary TX mod concerns the plate tank of the final, it substitutes a larger coil and replaces the capacitive coupling to the antenna with a loop inserted into the new tank coil.

I did this mod on my Twoer but output is almost exactly the same as before.  Has anyone tried it in the past? If yes, any improvement?  Was the author exaggerating or did I do something wrong?

73, Bill NZ5N