I’d suggest just drawing the letters pixel by pixel yourself. Personally I only used a ad-hoc font that’s 3x3 pixels and with some fantasy it was rather simple to get some text on the poster (note I didn’t have to come up with more complex letters like B, so it might be harder for some languages).
The files in the fonts directory are only those used for the game to display text, but not the image assets. In fact, the fnt files only include the meta information necessary for the engine to know where in the associated PNG file the individual glyphs are stored (you can open the fnt files with any text editor of your choice).
Edit: I’ve found TTF versions of the font here (note I haven’t tested the downloads so can’t vouch for them):