Thank you very much for the information and links.
I do agree that the last known residence on the SSDI doesn't necessarily mean the person died there. However, from other research I know that he was a longtime resident of St. Louis and I think it's very possible that an obit would have been published there in 1982.
My local library no longer participates in the Inter Library Loan program either. I can order and pay for a newspaper search from the Missouri Historical Society, but understandably they will not search the whole month of July, 1982.
I will order the death record from Vital Records. Thank you for your help.