I'm getting 403s when trying to download basic census tract shapefiles. You might have the same problem / if you have regular jobs that rely on public datasets they may start failing randomly.
Looks like this might be another victim of the current administration's fun with databases (although I admit that's speculation).
If you can’t find it in the Internet Archive, you might have to file a FOIA request. Happy to pay for the FOIA request ($5) if made through https://muckrock.com. Make the request as comprehensive for the data set as you can.