Decompress Snappy files without missing stream ids and CRC-32C checksum

The iWork 2013 file format includes .iwa (iWork Archive) files stored in a ZIP file. "IWA files are stored in Snappy format, but they are not strictly tied to the specification. In particular, they do not include the required chunk of the stream ID, and the compressed chunks do not include the CRC-32C checksum." https://github.com/obriensp/iWorkFileFormat/blob/master/Docs/index.md#iwa

Is there a Snappy implementation that can decompress files that are missing from these components? If so, is there any sample code?

Sample iWork files can be found at the bottom of this page: http://fileformats.archiveteam.org/wiki/IWA . For example, unpacking the TestReport.pages.zip file reveals that it contains Index.zip containing the .iwa files.

I tried to decompress the .iwa files using the Snappy Windows command line tool: http://snappy.angeloflogic.com/downloads/ . However, I got an error: "Found invalid data while decoding".

I don't have any sample code yet because I don't know which Snappy implementation I should be using for my code.