I have an original sketch signed and dated of a clowns head by red skelton in 1991 He drew it on a paper table mat for me when I was working for PSA I'd like an idea on price thanks?

Well most paper table mats are reletively cheap but if some randomer with a colour as a first name graphitied on it it would probably make its value drop to 1 pence.
PS - Why do we need to know you worked for PSA?