Hi,
You may remove the h bridge if you use a relay with 2 poles.
For reverse, use the 2 poles on Normally Closed from the relay to turn the motor backwards. A switch will cut off supply when the motor is done rewinding. Use a diode to power a tone circuit in parallel to the motor.
For forward, the 555 will activate the relay, which will switch to Normally Open. That way, the motor is connected directly and the tone circuit is not operational because of the diode. Once the 555 is done timing, the relay will go back to Normally Closed and activate the rewinding circuit.
To reverse the motor when the switch is pressed while the motor is going forward, well, I haven't figured that out yet, but I will if I'm awarded the project =)
I have all equipment here to test locally and send you the schematic afterwards.
Ramiro