Thanks for the guidance. I found these hollow end rivets on the McMaster-Carr website. Perhaps one of these may do the job. The HTML page uses a frame set so the link I provided won't take one directly to the page for hollow end rivets. (For folks searching for the rivets, click the link above and then click "rivets" and then look for "hollow-end rivets.") Here's a screen capture of their hollow-end rivet offerings. It looks like 3 diameters (9/64" 3/16" and 1/4") are offered. Hopefully, one of these fits the diameter McIntosh used.