A few years ago, I sent off to the Smithsoian Institution inquiring about:
Captured German & Japanese Air Technical Documents.
The Smithsoian has a ton of this material, and it can be obtained, by filling out a request for that you can get from them @:
Archives Division, Room 3100
National Air and Space Museum
Smithsonian Institution
Washington DC 20560-0322
Initialy I requested a listing of files they had on various Japanese planes, and I receaved several pages listing referance material for all kinds of Japanese aircraft.
I can not recall specififcaly if I requested data on the Frank, though their are some files they list as having for it:
Real 3744 Frame 134
Title: New Japanese army aircraft Frank 1 and Peggy 1 and miscellaneous developments.
Abstract: Technical descriptions and discussion of the designe characteristiscs of the Army Fighter Frank 1,.....
I did get a ton of referances for the P1Y1, Ki-102, and N1K2, amongst other types.
This packet I sent to Pyro (I photocoppyed the one I received), some years ago, the donw side to this wealth of infermation is that it takes some time to get it, once you fill out the forms it takes 8 weeks to get the material.
The documents in general come from:
" In the finial days of ww2 the advancing allies captured a number of German and Japanese documents on various technical subjects. The United states Army Air Force (later the USAF) had a number of these documents microfilemed by the Air Documents Divishion. Technical Infermation Section (T-2), Air Material Comand, at Wright Field, Ohio (now Wright-Patterson AFB). This microfilm serries containes documents pertaining to aircraft and aeronotical subjects, including aircraft manuales, flight test reports, and engenering studies of aircraft. The Material does not Include compleat sets of drawings for aircraft. Most of the documents are in the original language, while most indexing and tittle pages are in english.*"
* Although in the lists I have prety much all the material seams to be fully translated.