Since Entourage never intended this thing to run Google Market (Play) then it doesn't have an entry in Google's database. Simply put, Google has no idea which apps are compatible with this and which aren't.
The person who put together the ALLMINE programmed the Nexus as the device ID as it's the closest match to the PE. The drawback is that a lot of apps that are not compatible with the Nexus (that might be compatible) don't show up on the list, but still this is better than having no Google Market (Play) at all.
If you were to go about editing files to make it into another "device" then you might end up with an app that could possibly brick your PE.