Since you have CaravelNet, you can work out whether a room is likely to be solvable using the forum (at least assuming the spider is behaving itself, although it usually errs in the good way for this purpose).
If you click on High Scores up the top there, then click on My Stats, then click on the Number Of High Scores link for the hold you're interested in, you'll get a list of all rooms for which a high score exists but you don't have one. In this particular case, you should end up
here.
If you haven't completed a room and it's not on that list, it means that nobody else has completed it either. It doesn't necessarily mean that it's impossible -- you might always be the first -- but on a hold as old as this it's a safe bet that you shouldn't spend a lot of time on it while there's the rest of the hold to play.
That list is built based on what the spider thinks you've done, but in general when it's wrong it seems to not credit you for a room that you have solved rather than crediting you for a room that you haven't solved.
Edit: I should probably also mention that this won't reveal undiscovered secrets, so you don't have to worry about that. It will, however, tell you which levels have secrets before you've conquered the hold and that info shows up in the Restore screen.
[Last edited by Tuttle at 03-27-2008 02:28 PM]