I actually owned an antique metal clarinet for many years, but I never really learned to play it very well. One of my friends was a professional musician, and he played a few notes on it one time. It sounded fine to me, but he said it sounded a little tinny to his ears. He did like the feel of the mouthpiece, however.
I've looked on some clarinet websites to learn more about my instrument, and learned some interesting clarinet facts along the way. But apparently this particular clarinet is worth more as a musical collectible than an actual instrument.