The Chichester Festival Theater’s hit double bill of David Hare’s new “South Downs” and Terence Rattigan’s “The Browning Version” has firmed up its transfer to London’s Harold Pinter Theater, beginning perfs there April 19.Helmed by Jeremy Herrin and Angus Jackson, respectively, both shows star Anna Chancellor (“Four Weddings and a Funeral”) and Nicholas Farrell. Playful Prods., Neal Street Prods. and Robert Fox Ltd. produce. West End berths are filling up prior to the Olympics. As tipped in Variety (Jan. 30-Feb. 5), the Old Vic Theater production of Michael Frayn’s “Noises Off” has also nailed down a West End berth. The SRO revival of the classic farce has now confirmed a limited run March 24-June 30 at the Novello Theater.