Power armor frame (note)

Power armor frame is a series of four paper notes $$

Location
One can find this note for sale at:
 * Rowdy at the Atom Cats garage.
 * Proctor Teagan aboard the Prydwen.
 * Arturo Rodriguez' Commonwealth Weaponry store within Diamond City.
 * KL-E-0's Kill or Be Killed store within Goodneighbor.