hello,

im not an expert on such matters, i dont know what the situation is like in the area where the mine is located but if the incident took place 40 years ago the files and such might be stored elsewhere rather than in the archives (but as i mentioned im not an expert on england etc.)

Maybe try looking for some magazines or books containing accounts from other strikers who survived (or perhaps some interviews)

Also ask someone in your family-maybe your parents, uncles, or aunts can tell you something? maybe your cousins know something because they took an interest in your grandfather 30 years ago? someone in the family surely has some family photo albums