I came across this the site on DIGITALBALLPARK.COM of the Atlantic League ball parks. It's very outdated (still refers to the Ducks park as "Citibank") but it has links and pictures of the old ballparks that used to be in the Atlantic League like Nashua, Aberdeen, Qaukertown, Newark, and Newburgh.
It also has most of the current ones but it doesn't have Somerset, or York. Hopefully they update it soon.
Check it out!