Interesting. It appears that yours were canceled as precancels (i.e., prior to the stamp's placement on the document) as opposed to mine which was canceled on document. Are they all like that? If you have any with full cancel strikes on the document, I'd be interested in picking up some spares
I don't know if there were any full strikes. It will be another week before I can get back to NWPL and look.
Something else I didn't think about until now is if any of the documents are consecutive, could you match any precanceled stamps up with each other just for fun? In that case, I think it best to keep the 11 documents together.