@dcfyj row 12 clue 3 has to be 25 or 52 ("the Fourth, made with a First")
then row 23 clue 1 has to be 52 or 25 respectively
and it has to be over at the left because 2+5=7
and column A has nothing larger than 3, so row 23 begins 25
and in column B the 5 has to have spaces above and below
(because the "singles" are 5, but perhaps the reasoning that got me there was wrong)
so row 22 has a space in second position
so also in first position because just one number
which is impossible because no spaces in column A