Rust stains on 1936 sports postcards

take1

I have nineteen 1936 Champion and Triumph hockey postcards which have rust stains on the backs. Some more than others. The fronts seem fine. Can anyone advise me on the possible PSA grading for this type of flaw?? I don't want to send them in with little knowledge as to the possible grade/qualifier/penalty. Thanks!

angelenocarddude

check out this article, if you don't already know about this guy

http://www.sportscollectorsdigest.com/features/nerattowle

Griffins

is it rust or foxing?
Be careful who you send them to- some of the most noted restorers have damaged more than they've fixed.