Thank you for the mentions gentlemen!
If you had sent them here first Rod they could probably have been successfully restored. I'm honestly not too inclined to try to save what might be left because I have no idea what your people did (except unsuccessfully practice on them). I've never used Muggy Weld and don't even know if it's suitable to use under powder. You're probably relegated to painting them now. I doubt if outgassing will be an issue if you paint; it occurs when the parts are heated to cure the powder and all the trapped air and impurities in the metal come to the surface and blow right through the powder. Good luck!