I was in Harrisburg today for a conference at the Hilton. After my presentation, I escaped to de-stress by looking for a few benchmarks. I was on my way to the courthouse to look for D 397 when I spotted this "surprise" benchmark embedded in the sidewalk right in front of me!
Unfortunately the benchmark doesn't contain any information other than the elevation (as measured at some unknown date), and I wasn't able to find it listed among any local control collections. The disk is in good condition, but I have no idea how old it is or how reliable the stamped elevation might be.