My wife and I just put our rudder strap back on the boat last week and here is what we did. I did get some new solid bronze rod from Jamestown. The holes in our strap were a bit oversized for the rod. We put the strap on and then put the new rod in. I had large fender washers that I put on the rod against the strap as a spacer before I cut the rod. You can also just mark and cut. After they were cut my wife was on one side holding a sledge hammer to the end while I was beating the life out of the other end. We swapped sides back and fourth until the heads were where we wanted them. You are basically just making a man made two sided rivet. I was happy with the results and the strap won't be going anywhere. I would say you want to make sure your rod isn't too long because then it will be hard to hammer it. Don't over think it just whack it!
I had to replace the rudder on my Ensign. Getting ready to to re-install it and the strap. I dry fitted it and it's good to go.
FYI: Although the old rudder is repairable - with a fair amount of work - I did not have the time to deal with it in the middle of the summer. Got a new rudder from Ensign Spars - they were great to deal with (Bob Conkey). If you have to go the new rudder route be prepared to cut the rudder strap hole out yourself and fiberglass the inside of it - to keep water from getting into the foam core.