Just take your stock plate and trace it and then make holes ofr a 540 motor and cut it out. That is how I made this one.
I posted this trying to figure out if they are worth even worth the trouble. Nothing more. I am writing an article for a magazine - That is what started me doing this. I thought it would be cool to do a 540 converted MiniT.
To do one by hand - if you have a stock MiniT motor plate, you can do what I said above. if you can't do that, then me scanning it or taking pics will not help you at all.