Iq 1770

[Gojira]

I have completed the grid, and have the four extra words but at a total loss to understand the preamble and complete the shaded cells and find the venue, time and gift. Any pointers to help me would be much appreciated.

[ProfessorMaisie]

The letters you've put in the shaded squares are coordinates (the corner square - R/C - stands for Row and Column).
Take the first two surplus answers (the 8 letter ones) as pairs of letters and find where they meet in the grid - you'll get two 4 letter answers.
The next surplus word works in reverse - find the common symbols for this word in the grid and locate their coordinates (a 6 letter word).
For the next word the middle 2 letters are not coordinates - they're a 2 letter word linking the coordinates.

[Gojira]

Many thanks for the tip.