chewy - 4:03 am on Sep 11, 2012 (gmt 0)
I agree with the suggestion to ditch the motor(s). I had a similar one to your Evinrude and parts were difficult to find and expensive, and advanced repairs were impossible so I ditched it. So, a newer engine should be lighter and have more commonly available parts.
And I have an aluminum boat too, about the same age as yours. I use it about twice a year and haven't put a cent of money or hour of labor into it since I bought it close to 20 years ago. Of course, other boats are very different matter.
Oh yeah, I did put some electrical tape on a spot where a rivet popped out. The tape is still there, 2 years later.
Oh - are you replacing the floatation that was provided by the styrofoam that is usually under the benches? You might want to think about that along with center of gravity issues etc.