We have worked with Kings Mountain Historical Museum to digitize many large, detailed blueprints as well as other documents regarding the construction of the post office in Kings Mountain, North Carolina. These are now available on DigitalNC. There are 46 blueprints from the 1930s and 1960s, showing features of the floor plans for the post office as well as details such as mechanical and electrical plans, entrances, windows, lettering, lock boxes, and even the locations of plants. Additionally, there are documents about the construction of the post office and maintenance and repair over the years, giving insight into the communications between the federal government and a smaller, local institution in the 1930s and 1960s.
More materials from the Kings Mountain Historical Museum can be found through their contributor page, and you can learn more about them from their website and previous blog posts about a Civil War diary and Red Cross World War II scrapbook.