Sylvester Stallone First Blood II signed ink Autograph

This signed in ink autograph was sent to my son in 1982 from Sylvester Stallones Hollywood Studio . I still have envolope it came in I covered my sons name . It was a project for school in 4th grade to write to any of their idols . He was the only kid that had a movie star reply in his class . I have no idea of value of early ink signature by him the paper is pressed into by ink pen by pressure of writing .
Photo he sent and signed from
Rambo: First Blood Part II (also known as Rambo II) is a 1985 action film. A sequel to 1982's First Blood, it is the second installment in the Rambo series starring Sylvester Stallone, who reprises his role as Vietnam veteran John Rambo. Picking up where the first film left, the sequel is set in the context of the Vietnam War POW/MIA issue; it sees Rambo released from prison by Federal order to document the possible existence of POWs in Vietnam, under the belief that he will find nothing, thus enabling the government to sweep the issue under the rug.