Recent estate sale buy. Stanley folding box rule calipers. Nos 32, 36 and 136. 12 inch, 6 inch and 3 inch. The 3 inch has lost it's marking, but the impressions are still visible. I rarely see anything like this. There were longer rules, but they were warped. The husband or wife collected slide rules and pre electronic calculators. There were dozens large and small.
Those folding caliper rules are always neat finds. So many, many variations of folding wooden rules were made.