Has anyone had a diagnosis in their 50's?

Hi all, 

Over the past 18 months or so, my wife and myself have come to the conclusion that I could well be on the Autistic spectrum. My wife had a slight suspicion prior, but after I had a heart attack last year, it became more apparent, probably due to me being far too tired to keep masking as I was recovering.

We analysed my meltdowns / shutdowns (as we guess they are now and not just me going off on one), triggers, my aversion to noises (I can hear the hum of lights, fridge, electrical equipment etc. and always thought it was strange that I couldn't filter it out), dislike of bright lights (including sitting in the sun for any length of time) amongst quite a few other things and me being a thoroughly anti-social git (a lot of meltdowns always happened prior to going out to a social function, holiday with friends etc). 

This analysis led us to the conclusion and has helped up change things lifestyle wise and house wise to help me.

I've also been told by a Psychologist that it does sound like I am, but they don't have the qualification / ability to diagnose me and the NHS authority don't deal with adult diagnosis, so it looks like a private route would be needed.

Although I'm only at the start of trying to determine whether I should get an official / medical diagnosis, I'm just wondering if people my age (nearing mid 50's) do ever get diagnosed and what, if any, advantages does the diagnosis have, aside from peace of mind and an understanding of why I am like I am?

Thanks.