nukecad and Augeas - thank you so much for the kindness of a reply. You asked some question of me. Below is my response. Some answers are incomplete. I'll add to them in a couple hours as I can.
Best wishes to you, Janet
nukecad:
Are the hyphens/underscores at the start of the filename or somewhere within the filename?
The hyphens are located throughout the file names, albeit many files belong to a group of files following their own unique file name pattern. An example would be where I downloaded monthly activity from the same institution for many years and possibly multiple accounts. An example would be files named Stmt_2015-12-10.pdf to Stmt_2022-12-10, of which there are potentially 300+.
I will follow up with example names of files at issue. I wrote the names to a list; if it is as accessible as the name implies, I'll provide it soon.
Where are the files, on a memory stick?
The files are being recovered from my hard drive, specifically they had been in C:\MyDocuments, several folder and subfolders deep. I'm writing the files to a memory stick (i.e. USB drive.)
Augeas:
What is the file system?
I don't know that means. I'll google it and let you know.