Identifying IWC watch

Hello,
I inhereted a retangular 18k gold, six jewel IWC quartz movement. The case has serial # 2301730 and the numbers 3870 below. It has the original tan pig skin watchband.

Identifying IWC watch

From the "date your IWC" utility and when only entering the case number (you need to get an watchmaker to open the case and give you the actual movment serial number to be more accurate) - the utility responds with : The case was most probably produced resp. delivered around 1982.