This is probably a dumb question, but did Viren's Onitsuka Tigers that he wore, winning the 5000m and 10000m, in Montreal have a spike plate?
I still haven't found pictures to confirm this. The following picture indicates they actually may not have:
https://c8.alamy.com/comp/GB7RCY/athletics-montreal-olympic-games-1976-mens-5000m-GB7RCY.jpg