I actually never have; but my grandparents [RIP] were in the deer hunter. They actually can be seen at the end of the wedding reception scene, sitting down, IIRC. It was filmed at Lemko [sp?] Hall, which was right across the street from where they lived. They actually got the chance to meet De Niro and the crew too, who invited them to dinner.
BTW, this was filmed in Cleveland, the Tremont neighborhood. Now, the Hall has been renovated for condo's and an art gallery . The yuppies are a big influence of the neighborhood now with many residents.