Recently in years, myself and members of the Retired/Former FBI Agents Society have noticed many Hoover signed documents appearing on Ebay and other auction areas. The prices range from small amounts to those which are really outrageous.
With regard to the "value" of a "blue" Hoover signature, I can't say myself. Suffice it to say there are literally thousands of letters out there from him to both insiders and outsiders. Personally I can't find anything "rare" about them but I guess the value is in the eyes of the buyer. Certain specific letters and their contents are needless to say more valuable than others. You'd probably have to examine each item on a case by case basis. With exceptions, I think you'll find that anything signed in "black" was probably done on auto pen and is virtually worthless in my own opinion.
For many, the question of what did the Director "sign, and not sign" is an issue. Especially with collectors. In 2007, I ran down two former FBI employees who would be in a position to know. Lou Bracksieck, mentioned below, is a retired Agent now and an old friend of mine from the early 70's when we gave tours together, prior to becoming Special Agents. Many thanks for his, John Fox and Virginia's input.
In the meantime, here's Lou and Virginia's input on the Director's signatures:
" Larry, Here is some information to help with the signature issue. Mr. Hoover personally signed only in blue ink - Schaeffer #252, I think Blue Peacock. He personally signed all letters of commendation and censure, congratulatory letters such as anniversary and retirement letters, and, of course, personal correspondence. He also signed all photographs. Anything in black ink came from the auto pen. Miss Gandy did sign various letters. I speak with some authority since I worked in his Telephone Room from 1969 - till his death."
Lou Bracksieck 64-96
"Larry:
The non-routine correspondence was prepared on the small "Director's Office" stationery with BLUE letterhead and was signed by JEH in BLUE ink. If the ink was not BLUE, he did not sign it.
He made many a note in the margins of memos, etc., in BLUE ink. He used BLUE ink when autographing photos, books, etc. I have two autographed photos and a "Master's of Deceit" in BLUE.
He also addressed SACs and other Bureau officials by their last names only - e.g. Dear Smith. If the individual was not in his good graces, it was Dear Mr. Smith.
My father, William Alexander Temple, EOD 1926, died 1961 in Springfield, IL, at age 73 (a reemployed annuitant). He was the first fugitive supervisor in the 20s and participated in the Lindbergh Baby case and assisted in Machine Kelly's arrest.
My husband of 52 years, James Crookston, and I EODed together 3/19/56 and retired together 1/2/89. Jim spent his career in Records Management while I was in the Personnel Section."
Virginia Crookston