Charlie Grapwin "Uncle Henry" of OZ Autograph - RARE!

One of the "holy grails" of OZ Autographs, "Uncle Henry" played by Charley Grapewin

Vintage fountain pen signature, “Sincerely, Charley Grapewin,” on an off-white 3.75 x 3.25 sheet affixed to an 8.5 x 4.25 sheet. In fine condition