Dear Mr. Morrisson,
Thank you for posting your request on History Hub!
We searched the National Archives catalog and located series titled Numerical Files, 1906-1910; Central Decimal Files, 1910-1963; and Subject-Numeric Files, 1963-1973 in the General Records of the Department of State (Record Group 59) that are arranged by various State Department filing systems and may be useful to your research. More information about the files in RG 59 can be found here.
We hope this is helpful. Best of luck with your research!