You may find this info from ARRL luseful for acceptable verification of license:
Exam Element Credit
For General written exam (Element 3) credit, persons who took a 50-question Technician/General written exam before March 21, 1987 receive Technician grandfather license credit per FCC Rules.
This can be verified if an applicant presents any of the following:
-- Per FCC Rule 97.505(a)(4)s, a FCC Technician license issued before March 21, 1987, as indicated on the license.
-- An original Element 3 Certificate of Successful Completion of Examination (CSCE) issued before March 21, 1987.
-- If licensed in the mid-'70s or after, FCC will issue a 'License Verification Letter' indicating that the applicant was licensed as a Technician licensee prior to March 21, 1987. The FCC stated any requests for verification must be submitted in writing to: FCC, ATTN: Amateur Section, 1270 Fairfield Rd, Gettysburg, PA 17325. The request must include name, address, telephone number, date of birth, call sign issued at that time, and when the Technician license was granted (if exact date is not known, give the approximate time frame). The FCC asks those inquiring to include any information that may be helpful in researching these requests, but it does not need to know details of the examination session, such as where the test was administered or who gave it. "These requests must be researched on microfiche, so they will be very time-consuming," an FCC spokesperson said, adding that no one should expect an overnight response.
-- For 1966 or more recent records, the FCC's research retrieval service contractor, Best Copy & Printing, Inc. (BCPI), will obtain the pre-1987 technician certification from FCC records. There is a charge for this service. For assistance in purchasing copies of FCC documents, please contact BCPI directly. Phone: 202-488-5300 or 1-800-378-3160. TTY: 202-488-5562. Fax: 202-488-5563. Email:
fcc@bcpiweb.com. Web:
FCC BCPI | Research Service Pricing.
-- A 1987 Edition, or earlier, Radio Amateur Callbook listing is acceptable as proof provided the 'T' (Technician) license class appears on the page next to the call sign listing. Only Callbooks issued Fall 1967 or later will show the license class. Be sure to copy the year of publication reference, if not printed on the page.
Visit
Internet Archive: Digital Library of Free & Borrowable Books, Movies, Music & Wayback Machine for an archive of old Callbooks. The books are searchable PDFs.
-- QRZ.COM has posted on their website a copy of their very first Amateur Radio CD ROM product as originally published in 1993. This searchable database contains license records from 1983 to 1993. A printout of such a listing from the CD ROM or the web page, showing a Technician license effective or begin date prior to 3/21/87 is acceptable.