Get proper advice, you need a lawyer not an internet forum.
The moral conundrum… Well, myself, I had a gigantic NHS ****up which has left me fairly screwed in some interesting and permanent ways. And after recovering my notes, there’s little doubt I’d win any case, and given the damages caused apparently I could expect a decent size payout.
But, other than that I’ve also had a lifetime of great care from the NHS and frankly I feel I’d have to be a total git to go after them. And the consultant responsible isn’t around any more so there’s no question of preventing it recurring. But this is very much a personal thing, I’m not sure there’s a right or wrong but it wouldn’t sit well with me.