Many thanks for all the information.
I bought a Raiders poster, 27" x 41", with an NSS code, logos, etc. Will look to post a picture.
One thing I've noticed is that pictures online of the 81 Raiders poster appear to suggest variety in the colouring. Sometimes it appears quite dark brown and earthy, and at other times quite orangey.
I don't know if there actually are differences in the flesh, perhaps due to different printers and print runs (as Jeff notes there would have been), or if the apparent variation is just down to the way the picture was taken, the lighting at the time, etc.
Anyway, I'm very excited to own an '81 Raiders (I can remember my grandmother having to take me to see it when it came out). I've been looking online for any discussions about the merits of the '81 poster versus the one Amsel produced for the '82 rerelease. For my money, the '82 poster is very cool, and iconic, but is more leightweight and comic booky. The '81 poster to me better evokes the mood of the film, its pulpy origins, and the feeling of being something 'from the past'.
Desk