After printing the head in PETG using Kayl's original files, I printed the original separate eye file. I just couldn't get the eyes to fit.
I remixed the original eye file left and right pieces in Prusa Slicer; stood both items to full vertical, and then reduced the height dimension only to 93%; Sliced and reprinted.
Resulting eyes snapped into place in the printed head perfectly and are secure without having to use any glue.
Thanks to the original publisher for a great and functional bank that my grandchildren are going to love when they receive!!
The author remixed this model.