On the archive.org website I have found two books showing the musical instruments collection of a museum in Cöln (Cologne).

The second volume of the catalog describes the plucked instruments. For this article I have selected the mandolin family and extracted the pictures. The quality of those pictures  is not the best, but they are very interesting anyway.

Musikhistorisches Museum von Wilhelm Heyer in Cöln : Kleiner Katalog der Sammlung alter Musikinstumente, verfast von Georg Kinsky

• 1. Band: Besaitete Tasteninstrumente. Orgeln und orgelartige Instrumente. Friktionsinstrumente. (Part 1 stringed keyboard instruments, organs and friction instruments)
• 2. Band:  Zupf- und Streichinstrumente. (plucked strings instruments and bowed instruments)

Pictures of mandolins, pandurinas, mandolones and colachons

Klick on any image to open the gallery – from there you can download the pictures in a higher resolution.

Additional Information:

Doppelmandoline in the Museum für Musikinstrumente der Universität Leipzig

Mailänder Mandoline

A gallery of guitars from this book is available in my other blog gitarrenbank.de:

• http://gitarrenbank.de/die-gitarren-im-katalog-des-musikhistorischen-museums-coeln-1910-1912/