Almostsuccess!
After literally half an hour of further effort, I managed to get Dasher to link when built against the Maemo Chinook SDK. Hurrah!
Okay so it took a manual edit to the Makefiles. I think I’m going to have to consult somebody who knows this whole autoconf/automake business a bit better to see how I can get the Glade libraries referenced properly.
Then I need to get it to actually start up as it currently tries to dereference a null pointer and segfaults. This is probably due to my fairly cavalier #ifdefing out to get it to compile. Now I need to go back and figure out which bits are actually needed and how to get them to work.
Ultimately of course the UI under Maemo is going to be a bit different, especially once I get the thing working as an input method, but for now I just want it to work at all!