Dear colleagues: The Italian engineer Roberto Guatelli was a world-famous model maker. He built many models based on the drawings of Leonardo da Vinci for IBM New York. Moreover, he made replicas of important historical calculating devices: machines of Pascal, Leibniz, Babbage, Hollerith and Steiger/Egli (Millionaire). Several replicas are preserved in collections in New York, Ottawa, Mountain View, Pittsburgh, and Milan. I am very grateful for information on additional replicas: a) Did Guatelli build replicas of other calculating machines? Which? b) Have these replicas survived? c) Where are these replicas? d) Do you know more about Guatelli's life? Many thanks for your help! Best, Herbert Communications of the ACM: The Model Maker of Leonardo da Vinci, Blaise Pascal, and Charles Babbage https://cacm.acm.org/blogs/blog-cacm/233366-the-model-maker-of-leonardo-da-v... Meilensteine der Rechentechnik, volume 1 https://www.degruyter.com/view/product/480555 Meilensteine der Rechentechnik, volume 2 https://www.degruyter.com/view/product/503373 Amazon https://tinyurl.com/y9upwagp ETH Zurich, Department of Computer Science Bruderer Informatik, Seehaldenstraße 26, Postfach 47, CH-9401 Rorschach, Switzerland Telefon +41 71 855 77 11