No they are not identical.... TomTom use 3 different screen versions in the 520/720/920 range
You have to open yours up and see what screen type it is from the numbers on the back of the screen, then order the correct one as they are not inter-changable if you order the wrong one. Make sure you order the same type as yours.
I bought one of the Chinese copies for mine & for about £35 (Screen & Digitiser), went straight in and works a treat. The sreens are very easy to fit.