Upon completion of the sundial Paul contacted me to discuss why the sundial time did not agree with "clock" time. I had a nice discussion with him about corrections for the equation of time and for local longitude. Keller Engineering wrote up an explanation of these effects and erected a plaque at the site to help visitors compare the sundial's time with their watches.
If I am ever near Hollidaysburg I hope to visit this terrific sundial someday.