I bought mine here:
http://www.woollyhatshop.com
I just searched for a 7 speed one:
Shimano STX RC/LX/Alivio/Acera 7 SPEED Replacement Freehub Body FH-M290 -
Y3AP98020
http://www.woollyhatshop.com
I just searched for a 7 speed one:
Shimano STX RC/LX/Alivio/Acera 7 SPEED Replacement Freehub Body FH-M290 -
Y3AP98020