Cases XX Tested Cleaver

[amx686970]

I just picked up a meat cleaver marked Cases XX Tested.  I can't find much online about it though.  I did go to Case online and see that Case's XX Tested marking denotes this is between 1932-40 but mine doesn't have the apostrophe in the name.  It looks original and in nice condition.  Any ideas about this marking?

Thanks,
Robert