In a long shameful convoluted story, I find myself with a new tricked out MacBook Pro 16", and a Time Machine brain transplant from the last machine. Not yet fully cloned. New MBP runs only Catalina. Apple has seen fit to -- get this -- prevent users from writing to the root directory of the filesystem.

Now I need to figure out how I want to map a nearly four-decade-old directory structure to the absurd dictates of my new environ.

jojo69's hell may be different - dunno.