I found an article in Military Collector & Historian, the Company journal on US Army Hardtack boxes from the Civil War
"Union Army Hardtack Boxes of the Civil War" by James R. Loba and Leslie D. Jensen. Vol 48, No. 3, Fall 1996, pages 124-127. Teh article contains 4 photos and some drawings.
This issue is available for sale on the website. See link below.
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