The correspondents in A.R. Gurney's Love Letters are well bred, well-to-do, and well meaning. Those in George Brant's Lovely Letters: A Correspondence of Love are shallow, selfish, hypocritical, and materialistic and draw little smiley faces in the margins of their letters. But though Brant's parody satirizes, among other things, the military, the Peace Corps, the snack-food industry, fraternities, capitalism, and Gurney's play (with its numerous guest stars), at no time does he stoop to mean-spirited ridicule. The unpleasant protagonists get what's coming to them, but just when they despair of finding any meaning in their lives, a plot twist redeems their undeserving souls and sends us home hauling out our hankies. The Zeppo Productions show has been tightened up since its long run at Cafe Voltaire and now clocks in at just over an hour. The role of spoiled Jane Pennington is now being played by Kate Fry, with Brant again playing the rapacious Richard Johnson and Darren Bochat reprising his role as the faithful and sensitive mailman ex machina. Factory Theater, 1257 W. Loyola, 274-1345. Through October 9: Fridays, 10 PM; Saturdays, 9:30 PM. $5; $8 for Lovely Letters and Bitches (see separate listing) the same evening.