"The Grapes of Wrath." Metacom. John Steinbeck's classic novel of the Depression gets truncated treatment in this one-hour evisceration. If that weren't enough to sour your aural sensibilities, note too that this is a copy of an "NBC Theater" presentation made for radio listeners 37 years ago. As such, its only saving grace is the commanding presence of the late Jane Darwell, whose Ma Joad in the film version won an Academy Award in 1940. The reproduction is irregular and the music mawkish. Commercials for other Metacom product fill out the tape.