Hello Cole!
I'll help you real quick with the few things I know about these, others will chime in later to give you answers as well, no doubt. This is a 1937 Portuguese contract bayonet, can't tell you more about the WaA253 other than I've found it on a Spanish contract one I have. I'm sure you'll find which maker this inspection stamp is linked to I'll try to refresh my memory in the process.