Blue with slate grey is dated 1990. Held to light, no visible penetrations can be found.
White with orange is dated 1991. Held to the light, no visible penetrations can be found. An opaque dot is present as pictured, could be oil drop but not greasy to the touch.
Red with chartreuse is not dated, but thought to be 1985. See notes below detailing email exchange with OS Japan to confirm this. When held to the light, this poster has approximately 13 penetrations occurring on folded corners (see photo), with some staining as well.
From: OS_Shimazaki Sent: Thursday, November 9, 2017 1:58 AM Subject: RE: Os engine full line up poster
Hello Mr. Cottington, Guessing by the engines on the list, we think it was printed in 1985 because 91FSR, which was made in 1985 is in the list but FF240, which was made in 1986 is not in the list. Best regards, Junichi Shimazaki
I have additional pictures and will add them to this listing upon request.
Asking $18 for the lot, including priority mail, padded envelope and tracking.