The Brooks Pro- small rivets was the OEM on my 1973, Raleigh Pro Mark IV (purchased in 1977 on consignment from a former co-worker who left Evanston for the sunny shores of CA). Back then we'd pay dearly to have the big rivets added by a local leather worker as the Team Pro was very hard to obtain in the Midwest. Since I was formerly very light (~135#), I did not experience the need for the big rivets' help in securing the leather to the rails--- although as a pro shop rat, we all lusted for the best- those big rivets on the Brooks Team Pro!
Paul Dieterle
Wheaton IL