What makes you so sure the coin is from Nawanagar?
The important part that differentiates it from the identical design from Porbandar is off the flan, even early coins from Kutch are similar, all 3 bearing the name of long dead Muzzafar shah III but each one has a short nagari name below as the only sure way to identify them, sri jam for Nawanagar, sri rana for Porbandar, for Kutch the actual name of the ruler
