Transom rivets

[79basstracker]

Hi everyone! New guy here. I'm in the process of restoring/remodeling a 1979 Bass Tracker. I'm currently working on replacing the transom and I'm in search of some solid rivets that go through the transom itself. The rivets i have removed measure roughly 1-3/4" in length, probably closer to 2" before being bucked. I can easily find the shorter lengths but these seem to be harder to find. Any and all advice and info will be greatly appreciated! Thanks in advance.