try edit the build.prop? there you can change it. a bit sloppy way of porting a Rom. hope you guys don't get problems installing apps from android market not targeted to your phone.
me thinking loud.
I'm not discouraging you. keep the good work ;)
Phone: Sone Xperia Z 6603
Kernel: Stock + Rooted
ROM: Stock + Removed Bloatware + Minor tweaks