For anyone who's interested, I followed this advice and found this video...and I'm blown away. Before this thread, I didn't even know what a planishing hammer was. I'm a novice on metalworking (other than grinding rust off of steel-hulled boats), but someday when I have a shop, I want oneThere's are some guys on youtube that will blow your mind with actual planishing hammers
Look up Lazze, Ron Covell and Tinmantech
https://www.youtube.com/watch?v=sK0oGJEf1Hk