Quietly staid but totally charming Gwendolyn uses no kitchen techniques or technologies later than those of the 1850’s. Evenings, choose between 3- and 5-course tasting menus (note: each course offers two choices). An amuse-bouche of two oysters got us started (one fried with an impossibly delicate crust and one raw with a tart mignonette), then came a choice of a salad (bacon, onion, and watercress) or a svelte buttermilk, dill, and cucumber soup. Next was beef carpaccio with paprika oil or savory little pizzettas with mushrooms and cheese, followed by main courses of mahimahi or pork, the preparations both modest and exquisite. In short, Gwendolyn is a flawless gem. (8/13)