Not a specific catalog, but here is a page with the link to the "USPS forms" database within the postal history grouping at the StampSmarter webpage. (I linked one level up here to give you an idea of some of the other potentially useful projects at this site):
https://stampsmarter.org/features/H...eatures.htmlThe USPOD/USPS had thousands of different forms in countless editions over the past 200 years. The challenge of collecting and cataloging them is the immensity of the task. Most of them have very modest monetary value (including yours) because of the low demand and the fact that they are often found in bulk quantities. However, they can tell quite a lot about how the mail moves and how the post office operates - both visible to the public and behind the scenes.