Here's a page from a price sheet from Sandruck's Bike Shop, Baltimore, about 1964 (post-Record rear derailleur, pre-Nuovo Record). Note the item numbers 1036/1A and 1036/1P:
http://www.wooljersey.com/gallery/aldoross/pd/1036+1A+1P.JPG.html
Aldo RossMiddletown, Ohio