George pointed me to this photo that was on Wikipedia. He says that the original photo that I posted here was probably a patriotic reply to Chiang's original carving, of which there are several.
A couple of days ago I posted some 1962 images from Kinmen. One of them showed what appears to be a slab of cement with writing on it. Les commented: "There is a date on the bottom, November 17, 1961, written in Chinese characters, plus another date written in Arabic numerals. That one is sometime in 1960. The rest looks like lots of scribbling. Maybe just graffiti."
Sarj rescanned the photo and cropped it to give a better view of the characters on it. Click on the image to see an expanded version. If you see anything here that you can identify, please leave a comment.