Dear David,
I played Mahler 9 not so long ago.
As I just checked my score, there are no glissandos in F dur with c# in it…?
On the last page :
1. gliss has b, es and as / in the last moment you change as to a ( dont play the glissando too loud because of the pedal change 🙂 )
2. has b and es (there is no dynamics written, I was supposed to play p with cresc here)
3. and 4 gliss have cis and fis
5. gliss has b and in the end you step on fis (also piano with cresc.)
Damp all glissandos quickly.
Hope it was helpful.