I finally did get it to compile for 770 with the old scratchbox. Here's the deb of maemo-mapper 1.4.4 (unmodified) for os2006 2.2006.39-14:
maemo-mapper_1.4.4-1_armel.deb

and here's the deb of my modified version (also for os2006 2.2006.39-14):
maemo-mapper_1.4.4-1-mza_armel.deb

Both work fine on my 770.

Here's a screenshot:


enjoy!