Three months after purchasing The Tavern at River Falls on River Road, RW Restaurant Group has begun to put its mark on the Potomac Village institution. “We’ve gotten rid of some dishes that weren’t selling, and put our own spin on the dishes we kept,” says Tavern co-owner Frank Shull, who operates 11 D.C.-area restaurants in a partnership headed by famed chef Robert Wiedmaier. The changes started with the bar, where Shull says customers will find “better beer, better wine, better cocktails.” The menu is getting shorter but higher in quality, Shull says, with new dishes including swordfish, grilled calamari and stuffed baked oysters with crabmeat. Coming soon: nightly drink specials (margaritas, mojitos and blood-orange crushes) and an extensive brunch menu on Saturdays and Sundays. Even the restaurant’s name is being streamlined, from The Tavern at River Falls to the shorter River Falls Tavern.  Under the RW umbrella, the Tavern is now a sister to such popular Wiedmaier restaurants as Marcel’s, Brasserie Beck, Wildwood Kitchen and Mussel Bar & Grille.