I don't own one and it's been a while since I've seen one up close, so I may be entirely wrong, but I think the frosted look was created by sandblasting the interior of the shell, not by painting it. If so then there would be no way to remove the effect, short of a very major polishing job.

As far as i know Fibes never painted any of their acrylic drums.

If you have one that is ,it's not factory original.

I've got a few crystalite Fibes snares and complete kits. Some are clear and painted on the inside like the 'black beauty' and a powder blue kit (still looking for a matching bass drum) but the smoke finish is in the acrylic itself.

I can take some pictures and give you more info if needed but this is my quick take on your question.

Regards, Peter