Back Case of Mid 2010 Model

Hi,

I want to replace the Front glass of my A1278/2.66 GHZ Intel Core 2 Duo MBP. Using the MAC ID process of your website it has been categorised as MID 2010 13" MBP .The installation guide on your site says that there are 7 phillips screws and 3 13.5 mm phillips screws on the back cover. But on my macbook i find hat all ten screws look the same size. Im now confused whether to purchase the display LCD as identified by your website OR if the MAC Identification process is faulty. Please guide so that I can decide whether to go ahead with my purchase or not.