Ah, that's a difficult one. The font is not embedded, but specified as being "TimesNewRoman". Thus, a "Times" variant font will be used - and unfortunately, it doesn't have the right characters present. We ship the "Ghostscript" variant of the PDF base fonts, and of course you can replace them. However, they are in a slightly exotic format. So it is not easy unfortunately, and the font file names are hardcoded. But you can give a try to replace them by, say, a renamed variant of a Times font that does have those characters.
I'm not entirely sure if that will fix it, though. Getting from character info to a specific glyph in a font has become a bit overwhelming since the days of ASCII code pages...