I really don't know where to start - first of all, installing a TTF font will only help if TTF fonts are being used to render the character. If, for example, you're on a virtual console, then you'd use the tools 'consolechars' and perhaps edit the font table with 'psfaddtable' and similar tools.
On my system the man pages always show me (C) (*not* the copyright symbol) so I don't even know where to begin sorting out what ultimately renders the text in your case.
I wasn't correct before when I said it's a 'missing glyph' - it occurred to me later that the glyph could in fact be there, but if it's not properly mapped to the font(s) used for your locale then as far as the system is concerned, no glyph exists for that specified character code.
Perhaps you can find some clues here:
(But one of the most important parts - creating the font map file - is barely existent)
Unfortunately I can't comment on the font map file either since I don't know its structure as used by X or the console.