While browsing the Miele homepage for some advice for sudsmaster's "fluff" trap, I noticed that Miele maintains a "swap your vintage Miele" exchange platform on their very own page:
go look for "Sammlerbörse" (collector's exchange) on www.miele.de... or click the link below.
Here is the introduction text translated:
"Important notice: Dear customers, having received different inquiries about historical brochures or articles, we took to offering you the opportunity to expose your historical Miele articles or appliances, here on our internet pages. You can offer or search for old books, leaflets, advertisment signs and appliances. However, this is not just a trade market for used machines. Any appliance offered here or looked for should be older than 30 years. We will check the compliance to this rule on a regular basis and will retain the right to delete any such non suitable classifieds."