And then it hit me....

[Alfred Thompson]

The problem is that some people will use the cover of repair to add functionality. That is clearly unfair. I don't think anyone would have a problem with replacing one part with another that was the same. But where do you draw the line between this is the same, this is mostly the same, this is just a little different, and this is different? Who is going to monitor all this repair?
I like the idea (I think you - Joe) proposed earlier of a repair by petition. If something wierd happens a replacement part can be made. If that was rare and done with special notice than it can be more easily monitored.