The following list came from GHQ/SCAP microfich in the National Diet Library. The microfich numbers are AG(B)-01603 D-3 and D-4. The original doccuments were sent from HQ PHIL-RYUKYUS to CINCFE on Dec 16, 1947.
The follows are extracted from (1) old articles and (2) old-QSL collecting webs.
J2AAA (JA-CQ#3 1947) J2AAB (QST1946-11) J2AAF (JA-CQ#3 1947, QST1946-10/-11/1947-01) J2AAO followed by JA2AB (QST1946-12; by JA1FC) J2AAP (QST1946-12) J2ABC (JA-CQ#2 1946) Hank McTighe (QST 1946-10/-12) J2AHI Jan. 5, 1948 followed by JA2KG Lt. Lloyd Colvin W6TG [by G4UZN] J2AUW (QST1946-11) J2BAE Nov. 9, 1948 R.H.Gauldin W0ZTD J2BNR May 29, 1948 Emil Rettig J2EPK (JA-CQ#2 1946) J2EUG (QST1946-12) J2FOX Feb. 15, 1947, near Yokohama J2GHQ followed by JA2AV [reported by JA1FC] J2JSB (QST1946-11) J2POY 1948 followed by JA2BG [reported by JA1FC; by K8CX Joe Whitehouse "K8CX Collection"] J2RSM June 20, 1944, Irumagawa J2USA followed by JA2US [reported by JA1FC] J2UVW (JA-CQ#3 1947) J3AAA (JA-CQ#2 1946) J3AAD May 29, 1948, Kyoto Capt. Frank O. Stevens J3GNX followed by JA4AA J4AFA May ?, 1948, Iwakuni w/o Chandler RAAF J5ABA (QST1947-01)
The following figure is a call area map at that time, extracted from QST Jan 1947 (TKS TO JA1BWA).
These 1×3 format call signs above had used until Dec. 31, 1948, and then changed to 2×2 format. Here is a sample of the reallocation order, which states to change Major R. M. Lantz's call sign from J2GHQ to JA2AV (Microfich# AG(B)-01955 A-13).
Unfortunately, "Chart of Amateur Districts" and "List of Authorised Amateur Stations" are not attached in the microfich....