I don't think this is going to be as hard as you think. You could pull of the keys, shave the backs of them down flat, then glue on the bracket to the back and it should work fine. Making sure you shave them down ehough would obviously be the main issue. Yes, you would have to make custom keys or you would have to just live with the stock ones for all the rest.

As for the logo. You may be able to get a new cover and then cut out a larger typewriter icon over the apple one just so the outer shape of the typewriter is the shape you cut out. Then, take a black and white image of the typewriter the same size and paste it underneath that so it shows all the details. Keep in mind that you will need some cloudy arcrylic to replace the apple one. Not too sure how you are gonna find that one. Prob have to make it custom. I dont' know much about custom arcrylic work and/or making it cloudy. Maybe someone else can help there.
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