Took a long time to find this message from May. I found a link to https://www.sharedweight.net and
am not seeing its content.

Chris Brady shared a message about the groups.io platform:

"I have been using a tool called PG Offline to download the conversations, files and photos from this and a number of other Yahoo Groups that I am a member of. The files, links and photos are download as files within a folder structure on disk and the conversations/posts are loaded into a SQLLite database from which they can be extracted and parsed. 

At the moment I have the following downloaded/archived. 
As was mentioned previously, groups.io appears to have functionality to migrate data. It would seem worth doing this just have an online backup."