Thanks drxx and muraria.
My grid is full. I have the five extra words extracted (6,5,5,3,8). I hope it’s correct. It’s not leading me to anything glaringly obvious but the second word (5-letter adjective) is a synonym for a certain shape that I imagine is the second word of the symbol. I have been staring at different types of these symbols and trying to find obscure ones that are 10 letters long but with no luck. I even managed to find a copy of The Making of the English Working Class to have a scan through that but no luck. I have found an interesting character (initials JS) who may be linked to all of this?
Is the central area, containing all 15 letters, a simple 8x8 square in the middle of the grid? Or is it a more thematic, angry shape? Any tips or nudges about how to get the five shapes I need to add would be hugely appreciated! Thanks, H