Original Antique Concept Art Rendering North Avenue Svgs Bank Cambridge MA AL48

I am not 100% certain as to what these are but they look like they were used in the design process of some type of advertising or for use as letterhead. I bought a couple hundred of these with most related to banking institutions in the Eastern States. The Artist is unknown but these all appear to be from the same collection as they are itemized out by number and a drawer they were stored in. Please see the item photos and title for description and condition.These are in various conditions from poor to very good. I am not offering returns unless you do not receive the item or they are damaged from shipment. Thank you and good luck.