Thank you @gavinbaumanis. I think that Git may be the best solution. I have to look into installation on the server which is locked down pretty good.

I agree that some solution based on version control is definitely your best shot. At minimum, you should be able to ask things like, "what's different about the code on this server from what it's supposed to be", "when's the last time this file changed and how". That ability shouldn't stop at dev or qa, it should extend all the way out to production. Plus you don't want to reinvent or reimplement the wheel of getting the changes that are here up to there.

Also, using things like tags can help keep bookmarks of what code gets put into prod and what does not. You can say "This is release 1.0.1.5 -OR- tag something like 2024-01-29 so you can make issues reproducible and less chance for deployment errors.