The Broadway transfer of London hit “Mary Stuart” has set dates and a venue, opening at the Broadhurst Theater in April.Helmed by Phyllida Lloyd (“Mamma Mia!”), the production is set to star Brit thesps Janet McTeer and Harriet Walter, reprising their roles from the 2005 Donmar Warehouse staging and subsequent West End run. A new version by Peter Oswald of the 1800 Friedrich Schiller play, “Mary Stuart” chronicles the 16th century royal rivalry of Elizabeth I (Walter) and Mary Queen of Scots (McTeer). Play has not been seen on the Rialto since a 1971 revival. Production begins perfs March 30 ahead of an April 19 opening. The Broadhurst’s current tenant is the limited run of “Equus,” on sale through Feb. 4.