I have a rather large Certo poster that is dated 1928. The poster is in color and was professionally framed. It’s pretty much pristine except for 2 fold lines. I can’t find anything like it anywhere online and I have no idea how to determine a value. I have attached a (rather bad) photograph. If anyone could point me in the right direction I would really appreciate it.

Thanks! [img size=320]https://kovels.com/media/kunena/attachments/legacy/images/photo_43.JPG[/img]