If all fails & data is critical & you can afford you can give it to a Data
Restoration company.
It depends whether it's worth.

I was able to recover several times in totally hopeless situations with
corrupt MBR, viruses, etc. but it's for people for whom computers are "bread
& butter".
It's related to my profession.
But you sound like you could benefit from a professional resstoration
services, else you'd not be posting here.
You did say the drive was corrupt, so whether internal or external
enclosure, doesn't matter - something is bad with the drive logically on on
hardware level.

We had Senior EE engineer who has no clue of computers (yes it happens, he
is old!) whose hopeless situation was fixed by a Software Engiener as we all
worked together in the same company, one engineer helped another for free.
You're probably not that lucky.... give it to someone who might charge some
$$$ but if you want data & no backup, you're going to pay....