Question about these wheels

[Mr Chevorlet]

I bought these two wheels today and they are 16x6 GM with 6 lugs. Does anyone know what year they were produced. They are riveted instead of welded. Also you can see from the picture my 67 cap fits on them. I like to know it might make my search a lot easier if I know what I am talking about. How I found these my wife went on a drive in the country and drove by this place and he had all kinds of wheels on his property and I decided to stop. He was the nicest 88 year old guy I have every met. We fount the first two pretty quick. But no more on his 160 acres. Sorry for rambling. Here are the pictures maybe someone can identify. Thanks