Anyone know of a way to convert Thinktank DB files to some other format, or of a way to salvage a DB file if the SAV file is corrupted?

I think you can throw out the SAV file.

There's an export command in there somewhere, that outputs .HEAD formatted text. Are you on the PC or the Apple II?

I believe the SAV file is some sort of index file, it doesn't seem to work without it. If I use the SAV file from another DB then part of my data shows up.