FBI Mail Robot

This is a roughly 1/7 scale functional model of the mail robot introduced in season 2 of the TV show The Americans. https://uproxx.files.wordpress.com/2017/06/mail-robot.gif
I never planned to make "scale models of office robots from spy shows on FX" into a series, but here we are. https://www.thingiverse.com/thing:920194
I had always planned on catching up on The Americans, but didn't get around to it until last winter ahead of season 5. This project has actually been in the works for the entire past year. I thought that building it around existing electronics would make it easier than the Milton project, so I ordered the absolute cheapest line following robot kit I could find on eBay. It arrived very quickly but the package was missing literally 90% of the advertised components. The seller promised to send the rest, but after a few months of waiting for that to never arrive, I decided to put the project off until this winter. Eventually I ordered another kit which was still extreme