Horseshoe Pit and Mansfield Hollow Ballfield structure are not there anymore

Welcome to the forum! Appealing a rejected removal report here is the correct way to do this. One of the suggestions Niantic has made to help with reports is to make a splat:
Leveling Up Your Appeals and Removal Reports

Otherwise, submitting photos is the best way to show it doesn’t exist anymore. Can you show the date and gps coordinates, too, on your photos?

(edited to note that i have nothing to do with the appeals decisions. just trying to help another wayfarer)