Don't do anything rash take a little time let the pt alone for a while until the present disgust is over. Then check out what damage was actually done to the machine might not be too bad to have it fixed. Right now just be thankful no one was hurt and count it as a lesson learned the hard way and I'm sure you will be more cautious even without thinking about it to not flip the pto switch without something attached to it. You would have thought that it would have had a relief valve that would have opened up before any damage was done. The switch that the other poster posted that had the cover over it seems to be a good idea. I got one of those switches along time ago with the intent to put it on my pto so that it would be a deliberate act to start the pto. Some times just taking a little time away from a problem will give you a better feeling about it. You made a huge modification to your machine and I would hate to see you not get to enjoy the extra power that you have with the new motor in it. Glad that the missus wasn't hurt.