How do I fix broken session?

A crashing Ardour has had the most unusual effect; my tracks can no longer be armed!!!

The project loads and plays just fine, but I am unable to continue my recording.

Is there something I can do to (perhaps edit the session file?) to be able to record again?

My broken project file can be fetched at:

Please specify which version of Ardour you are using.

It’s an svn version of the 2.0-ongoing repository.
The checkout was made at 7th of August 2007.

I don’t have the revision number here, since I cannot access the studio until tomorrow.

If you need the revision number I will get it for you tomorrow.

After further investigation I have found out that the disabled record buttons are due to no inputs on the channel. So the actual problem is that the channel inputs have been deleted, and a fix is to add them once more.