Obviously you should not be simply relying on off the shelf items for such a restoration. When you set out to restore such a car - its best to invest in some real stuff, look up some vendors, there are lots of em and get their product shipped over. You can first talk to some of their seasoned pro staff before ordering.
The climate in Pakistan is nothing what happens in EU where there is snow - they throw salt on the roads to melt the ice, if you were to start a mehran in the morning and go to work, Im sure you would only have your keys the next day - the entire care would have been gone.