i can see why you’d take them off! I did the same with an old Monzani (well…there aren’t “young” ones, so…) and removed the thumb Bb key in order to use the other Bb touch instead.
Nice when you can switch things around to suit your hands.
I asked about the certificate because all Pratten models supposedly came with the “authenticity” certificate in the lid, but I don’t know when the stopped. Presumably when Pratten took ill before his death, but I don’t know for sure.