I am now all ready for my flight and have had some time to look at this again. Meursault, I have attractively in column 1 starting at row 1 and pyrotechnist in column 13. I am not completely sure this is correct but I can make it fit with the requirement for the 8,5s not overlapping with the 12s.
So far I have managed to hang a few more answers in the NW corner as s_pugh alluded to....time will tell.
sorry if I'm barking up the wrong tree, just in the spirit of trying to help.