Recovering old Usenet Posts

I also posted this in r/Thunderbird so no one has to refer me to there.

I am using Thunderbird 140.9 on a Mac Desktop. I use it for reading Usenet (yes I am a dinosaur) and using news.eternal-september.org as the usenet source.

Somehow, I managed to delete all of the messages I could see prior to Feb 26 for one of the newsgroups I read... long story. Is there a way that I could redownload messages for prior to that, say maybe 6 months?

Would the best solution be to delete the newsgroup from the feed and then reenable it? Or would it just start putting in new messages starting the time I reenable the newsgroup?

Maybe I could subscribe from another usenet provider to see the older messages, but if so, which provider. Suggestions would be helpful.

Thanks for your consideration.