The idea for a movie script in which a rich couple crosses paths with a deaf-mute chambermaid in a posh London hotel was still taking shape in director Michael Lindsay-Hogg's mind when he spotted British sculptor Henry Moore's Head on a Bone Base in the window of a Bond Street art gallery. ''I was so taken by the power of this strange little misshapen head that I decided this is what the rich couple should have and this is what the maid should steal,'' says Lindsay-Hogg. But, as The Object of Beauty crew later discovered, persuading the Henry Moore Foundation to lend them the four-and-a quarter-inch-high sculpture (value: $7,000 $14,000) was only the beginning. The director explains: ''When we placed it on the set's bedside table, we found that it was too small in relationship to the telephone and lamps.'' To right the aesthetic wrong, artist Derek Howarth, a former apprentice to Moore in the '60s, was enlisted to make three plaster and three fiberglass replicas approximately 1 1/2 times the size of the bronze original. Ultimately, the movie's inanimate star and its stand-ins split time on-screen. Only the close-ups focus on the bronze, while the scene in which the maid hides the sculpture in a sink of soaking laundry, for example, features the fiberglass version.