WWII Gov contract information research. Can you help?

I am trying to locate any information on a gun used to train with in WWII by the Army Air Corp. All my searching has come to little additional info. Can anyone tell me if data can be found using a specification number or a government order number??

What i am looking for is info on:
Mac Glashan Aerial training gun.
Model E-3
Specification number: 24,733 or 24.733
Order number: 42-19931

Anyone have any tricks to research this item? Any help would be apreciated. Ultimatly, i am looking for spare parts, part prints or a unit that i can back spec.

thanks

mjhenks

 

This is complete guesswork, but could the "42" in the order number mean 1942?

 

Gordon,

I believe the 42 does mean 1942 although i can not verify that. Do you know any resources to search old government orders or specifications?

thanks for the help.

 

MJ,
Not really in the US, but you could try NARA Here