I finally got 'round to uploading this pdf document on-line for everyone's reading pleasure.
The Index of Army Aeronautical Equipment with Navy and British Equivalents, Volume 5 - Armament, Revised 01 March 1944, a 400+ page document, is a master reference for armament and related equipment used in aircraft of the US Army Air Forces, including many used in aircraft of the US Navy and aircraft made by US manufacturers for use by the British Royal Air Force. Each item page includes an illustration, specifications, dimensions, and manufacturers and their part numbers. It is separated into 4 sections of pdf pages due to its size. You will find it at
https://aeroantique.com/pages/downloads, feel free to download it.
You will see that Vol 6 - Instruments, is already available/accessible on the same web page.
I have two more volumes yet to upload, Vol 2 - Landing Gear, and Vol 3 - Oxygen and Miscellaneous Equipment.
I am missing Vol 1 - Turbochargers/Pumps, and Vol 4 - Electrical Equipment. If anyone has these, please let me know and I'm happy to post them for ease of access.