Hi saoralba, I no longer have the puzzle but still have my worksheet; it's an anagram of
GoInG gReY (alternate letters) + W(abbreviation for with) + (dy)E.
I'm grateful for that help as I was convinced that 'lost' mean an E had to be subtracted. It's not an anagrind I've seen in more than 30 years of solving advanced cryptics.
Finished the grid and found place, date and remark but still don’t understand how to change the letters.Tried to get a name or a relevant word in the diagonal but nothing! Please help!
Jadzia, just take the letters on a trip - move them round on the …. The remark stays the same, in a different position - it'll alter some of the surrounding words.