On the plus side they have plenty of tread on the bottom and look ok apart from that. The crack never concerned me and its only the zip that has meant they need to go. Not sure how easy they are to get a new zip fitted.
If anyone's interested they are free. I have ordered myself some new boots so once they arrive they're available. I hate to throw away anything. I can e-mail photo's and I live Connor Downs.
Don't think a shoe bank will have much use for them