Recover raw Databases from corrupted MySQL 8 + Windows Server Implementation
Well, after three days of fighting with this, I have found a means of recovering at least some of the data:

With a lot of searching, I was able to locate an old virtual machine in the archives that still had a working copy of MySQL (5.x) that contained a version of one of the databases that I need to recover. From that resource I was able to generate all of the appropriate CREATE statements for all of the associated Schemas and Tables. So then, armed with my fresh server, and a new installation of MySQL, and all of the CREATE statements, I was finally able to regenerate all of the schemas and (empty) tables that this customer uses. So, upon shutting down the MySQL server service, and copying only the specific directories for that customer's databases into the new Data folder, then re-starting the service, the databases were, miraculously, fully restored!

IDK if it matters or not, but all of the schemas this particular customer had were MyISAM tables; I haven't yet tried this technique with any InnoDB tables, but this, at least, is progress, of a sort! Also, I don't know that I'll be able to find legacy functioning VM's for all of the schemas that I need to recover (and that are up to date/accurate!) so there's still a lot of work ahead... 

I find it stunning that there's no simple tool for analysing a backed-up raw MySQL Data folder and then integrating the contents thereof onto an active server. You'd think that such a tool would have tremendous value for innumerable people in situations like this!?

Anyway, back into the archives!