There's nothing remotely comprehensive about the whimsical selection of toys and books in the 200-year-old brick building that houses Tootsie's (555 Hudson Street, at Perry Street; 242-0182), framed by a green-and-white-striped awning. Children will seek out their own treasure here -- slipping a hand into the soft orange cat's belly to extract mice, small birds, and soft-sculptured hair balls. But what little kids do take home with them will likely get passed on to grateful siblings and cousins: the heavy-duty construction helmets, realistic enough to look a little like Con Ed's, and the gold dress-up shoes that come sized so you can actually walk in them. Kathleen Murphy, who opened the store's first incarnation five years ago, sweet-talked neighbors and friends into inventing and making several of the best toys the store has to offer. Wooden Emma dolls, for example, fashioned three blocks away, come in cardboard boxes made to look like brownstones. Despite a tenfold expansion in January (with a terrace and garden besides), Murphy has still scrunches the books and toys together the way she learned to do in the postage-stamp-size shop across the street. That way, room is left over for activities other than selecting toys. Up one flight of stairs, under-4's -- with adults to look after them -- can play all day (for $8) with wooden trains, kitchen sets, and assorted teddy bears. Next door, in an airy studio, children glue paper pepperoni pizzas together, with yarn cheese on top, in various classes or construct bug habitats at somebody's birthday party. On the top floor, parent support groups convene.