This is a finished painting, "comp" for a science fiction magazine, likely "Amazing" - created in the 1970s, and not used.  The site size is 22" x 16", acrylic on board, matted to 27"x 20" and is signed "Hinge" within the image top right (see photo).  My label is on the reverse, with indications that this was sold at a SF convention shortly after his death, 2003.  The varnished surface of the painting shows scuffs and abrasions from storage, which may be rectified by another coat of varnish or other technique.  (see main photo) the painting itself appears to be intact; it's the surface that is scuffed.  In any event, I have priced it to take into account that condition issue. The effort would be well worth your time!