It might work but I doubt you would see any improvement. The SAW circuit is usually used at much higher frequencies (> 300MHz) so it may need some adapting to go down to 455KHz. You would also have problems shifting to the opposite sideband . You wouldn't want a 455KHz resonator, you would need two, one about 453.5KHz and one at 456.5KHz. Switching capaciance across it as used in the original wouldn't allow for shifting up and down but you might be able to start at 456.5KHz and 'pull' it 3KHz down with a capacitor.
Brian.