For the Record

Today is the anniversary of my fathers death, he died 36 years ago very suddenly of a heart attack. I remember very little about him as I was only 12 at the time, I never had a 'grown up' conversation with him so don't feel like I know the real him.
There are so many questions I'd ask him, so much I'd like to find out but right now there's a very pressing question I need answering. 'What was wrong with your kidney's?'
The little I do know is that my Dad had problems with his kidneys, he had been hospitalised while still a young man and as he grew older suffered terribly with kidney stones. Family members know a little about his condition but nothing conclusive and so today I approached the NHS records office.
After my 3rd phone call I was put through to someone who said that his medical files would have been destroyed after 25 years, no joy there then. I've no one else left to ask and therefore may never know exactly what kidney issues he had.
My own medical records show that in 1975 and '77 I had procedures to investigate my kidney function by having  pyelography (Google it...it wasn't enjoyable at aged 10). Next to this information is written 'Kidney Disease', no explanation just those 2 words.
All of this I told to my consultant when admitted originally, all of it was dismissed without investigation.
I have another referral coming up, this time it'll be to the QE Hospital, Birmingham, I was hoping I'd be able to share some family history at this appointment. My biggest concern is that if there are any hereditary factors then my two daughters may also share this risk.
Without medical record evidence though I think I've reached a dead end, literally.