Yesterday I more or less verified my assumption by asking a craftsman:
'Olive' (in German) is called the little round metal plate surrounding a
keyhole. By analogy I could imagine what an olive is in plumbing.
Greetings,
Fritz
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Friedrich WAIDACHER
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Klosterwiesgasse 44, A-8010 Graz
Austria &
Tel/Fax 43-316-826264
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Moenchegg 34, A-8742 St. Wolfgang-Kienberg
Austria * * *
Tel/Fax 43-3578-8216 ;
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email: [log in to unmask] ''
http://www.webmuseen.de/Waidacher/
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