well from some of my travels in the americas its the type of thing i would not even flinch if I saw it. My immediate thoughts were:
1-folks are crafty, can easily take what north americans would view as garbage and recycle it into good use, even turn it into a buck
2-not as anal as we are; they might appreciate the end result that is this BTTF poster rather seeing it as an appalling travesty of a one sheet
I also thought it is extremely wet and hard to keep things in good condition; presumably this poster was kept folded and was completely soaked in the middle so this was all that could be saved
All this to say, I approve of this listing
A very good number of posters from Argentina have survived - dating back to the 1920s (if not earlier).
I wonder what that country's secret has been to keep folded posters that are 75+ years old dry, alive and well.
Here's an Arg OS I own.. for the flick,
Interrupted Melody (1955). It's
30 years older than the BTTF, but I think it looks pretty dam good for its age, and not the least bit soggy nor smeared with tempera paint.
(All the above is said very tongue in cheek, of course, Vick, as the BTTF poster could have been in terrible shape prior to its "surgery").