We have an Advertisement Post Card Massachusetts Co-operative bank league Vintage item.  It measures about 5 1/2" x 3 1/4".    It was put out by Massachusetts Co-Operative Bank League.  It reads "Your request for information about co-operative banking has been referred to the Co-operative Bank, your local institution, which will gladly answer your inquiries.  Massachusetts C-Operative Bank League.".  There is a preprinted 1 cent stamp on the front.  These (on initial posting I have a few) have not been sent/addressed, they are nos.

Advertisement Post Card Bank Vintage