I have heard of baking tapes in the oven to revive them although I've never done so myself. I did a google on "Baking Tapes" and got lots of hits. Good luck.

Is it playable at all? If you can find a decent cassette deck (even borrow one) and play the cassette right into a sound-input port on a computer, you would have a lot of tools at your disposal to eliminate noise, bring up certain levels, etc. There also are people who do this kind of thing for a living; best bet would be to ask around or ask people who transfer LPs to CD or videotape to DVD -- they may know folks who do this.

Thanks! Will look at both.