Based on what you showed, I would avoid it. It appears an easily matted undedicated vintage scrap of paper (always suspect in my book) signed in somewhat more recent filt tip (?). In any event, it does not appear authentic to me. Perhaps JoeW wil chime in?
I'm not super familiar with Peck's signature although, after reviewing several from trusted sources, this is not one I would invest in. Better examples out there.