Just wanted to pass along this link for downloading some helpful pdf files regarding WW2-era US AAC/AAF & Navy aircraft instrument information.
There are 3 primary documents available to download:
1) Index of Army Aeronautical Equipment with Navy and British Equivalents, Volume 6 - Instruments, Revised 01 March 1944, (downloadable in 12 separate pdf files due to its size).
2) Maintenance Interchangeability Cross Reference Charts TO-00-25-29, Dec 1943
3) Accessories for Airplanes-Engines Interchangeability Cross Reference Charts TO-00-45-1 dated Feb 1945 (only the pages which relate to instruments)
They can be accessed here:
http://aeroantique.com/pages/downloadsI hope that they are useful in your restoration or preservation projects.