Hi BT and Ryan,
You could do a lot better for $500 than an already mucked around with machine that's mismatched. That sort of machine will only ever be worth around $250 tops in its current state.
Come over to SA and you'll find plenty of these mowers still tucked away in old sheds ready to be re-homed. BTW I do understand that Victoria has the smallest SB population.
Cheers,
BB.