Unused Mint Condition Set 14 US Revenue Documentary Stamps 1963

$10 Internal Revenue UNUSED Partial Block Still Attached together at Perforations with border on bottom. Recently found in my Father's papers! Stamps are inadvertently attached to the back of the Authenticating Letter addressed to my father regarding usage from his lawyer on February 26, 1963. They can be lightly steamed off of letter! I have made no such attempt but have left exactly as I found them! Priced at $69 Each at Mystic Stamp Company!