I asked him to send me the image, and his findings, so that I could double-check things. He very kindly and promptly replied. It is a V-band exposure taken by Tom Droege from his home in Batavia, through the first Mark IV camera. I believe that the image was taken on Sep 17, 1999.
North is to the left, and East is down.
The plate scale is about 7.5 arcseconds per pixel. This is not a raw image. I don't know why one particular value should be favored so strongly. There weren't any other peaks in the histogram in this vicinity. This is not surprising for site in the suburbs.