The new lid works well and it is certainly good to be able to order replacement parts. Would have been even better if we could have just replaced the little plastic piece that fits on the locking mechanism (it had fallen off when we were away and our cat sitter seeming threw it out with the dirty litter). But we do now have a new lid and needn't replace the whole box.
The two lids came, because both latches had worn out, and they are quite a tight fit but hopefully they will get easier to handle with use.
Replacement lid worked fine if only I could get my cat to use the box! Can’t teach an old cat new things I guess!