I have severe dyslexia, dyspraxia and dyscalculia - I remember it being suggested by the headteacher that my parents place me in a 'special school for the slow' (don't come for me, that was the term they used), this was the very early 80's.
I was a perfectly functioning child outside of these issues and bright in all other areas of learning. I was quiet, well-behaved and happy to learn and to be at school - but they really really put pressure on my parents, hinting that I was a burden to the teachers, and I belonged in a place that 'would cater to my needs'.
The head had made a preemptive referral by telephone call to the special school in anticipation that my parents would say yes. There was no GP, no social services - just the head's opinion, which, in chatting to other people from that era, was how things worked in the early 80's
We happened to be moved for my Dad's job just after, and I ended up in a new new school (outside the UK) which didn't care and took me in their stride, and no more was ever said about it.
I only mention this just in case there is no paper trail with GP or school, if you go down the route of making a SAR, as there wouldn't have been in my case. The only reason I know about it is my own recollection and a conversation with my Aunt.