more information on the Museum of the History of Science collection
Museum of the History of Science
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Oxford OX1 3AZ
United Kingdom
Two records have come up for ear trumpets:

Inv 45501 Aural Ear-Trumpet, by F.C. Rein & Son, London, c. 1900

Inv 37401 Silver Ear Trumpets, c. 1860

so, in answer to your first question we have a very small selection.

Please see our online database via our website www.mhs.ox.ac.uk for more details and an image of Inv 45501. There is currently no image of Inv 37401.

45501
Image © Museum of History of Science