I have, I believe, is a model 72 Selectric II but there are no designations on the machine to indicate that. I believe it to be made in the USA but could not find proof...it used to belong to a community college in Michigan.  The platen size is 13 in and it has a fabric ribbon.  The ID #  is 26-1692017. The yellow sticker with patent numbers states it is Model 8X.   On the ribbon cover there are stamped several numbers:  1204149    76,      G-1.  There is a sticker on the inside of the cover, #473.  I looked all over the rest of the machine and could find no other stickers or codes.  
My guess is that it was manufactured in 1973 or '76.  Or was it neither?  Note:  I wanted to post a picture from my file but I can't for the life of me figure that out on this forum.