AOA brother,
i kept assista for more then 3 years when i was in Islamabad, this is first time i heard that assista comes with 1500 cc, might be their is.
i have the front original chrome grill so if you want to buy it i will give you at throw away price, coz its uselss for me now, the one is on your car is plastic made..
best of luck, and do mail me if you are interested:)