Alan,
They should not be too tough to get out, but I would be concerned about maintaining the shape as you reinforce them. You might want to make a jig to hold the unit while you do the reinforcing. It would be a bummer to have fixed and finished the cabinet, only to stress the repaired cabinet to the point that you re-crack the unit on install.
Also you need to research the zolotone on ABS. David Winick did his front end cap with it, but had to go through a multi product painting method to get it to bond properly.