I have found that if I scan my preprinted maps as supplied (trimming size from standard a4 to fit item) and upload each image, I can then use the advanded options to set image size via units rather than pixels to 7.5 x 10.5 squares and use the alt-grab to position for a near as dammit fit. Used it today for a session of Encounters and it worked brilliant.
Hope this is of help for other users :)