Hi,
Here's a [[Topic:DigiLand Tablet|link]] to the ifixit repair guides for some of the Digiland tablets. Not all the links to the various models have guides.
For a start diagonally measure the '''''screen''''' length from corner to corner. At least this will tell you whether it is a 7", 8" or 10" model, which narrows down the model choices a bit.
Have you checked the back cover just in case the model number is stamped on the case somewhere?