No. 1517: pseudonym by 29
…except 29 is a false PSEUDONYM. In four entries a segment of 29 is replaced by a word of four letters, making non-words. Taken in the order of the replaced segments these other words represent the real PSEUDONYM, to be written below the grid. In 21 clues a letter should
be removed before solving – these letters spell out a real example of the use of the false PSEUDONYM. Enumerations give the cells available.
Near full grid (have the 21 letters and 29a filled in + "3 of the 4" which need a change..)
10a Response from champion in game (4) O??O
7d Newspaper ready to accept something explosive (7) S?TONS?
Assume 1 of these 2 must be the "4th".....looks like 7d where TONS has replaced 3 letters from 29a but i am stuck now!