The finstall installer (that is: the backend and the front-end) now successfully installs a FreeBSD base system ("Amnesiac", which is the default name an unconfigured FreeBSD system takes).
Here are some screenshots of the current installer (the "novice" track, meaning as little interaction with the user as possible):
The first thing a user sees when he logs in as the 'install' user
Choosing the drive to install FreeBSD onto
Choosing the file system to use on most of the partitions
The last step before installation happens, offering user the opportunity to review chosen settings
The backend is visually boring, though it contains much of the most interesting work, so there are no screenshots of it.