At least one guy on reddit did this and is still sending out the files for people who ask: https://old.reddit.com/r/MouseReview/comments/enxzgg/lefty_g...

It seems like a massive pain though. Rebuilding a non-symmetrical mouse the other way would take electronics tinkering as well as 3d printing, and probably a ton of work to get all the connections and tolerances right.

I am left handed, and I use trackpads with my left hand, but I gave up on lefty mice years ago and use an ergonomic one right-handed.