Buchholtz,
The offerings by both Pelican and Autohaus AZ (along with other vendors in the USA) all have the same source: C&M Hydraulics out of Las Vegas, Nevada, USA.
These are all fully rebuilt and refinished. I installed their rebuilt power steering pump and the steering box/gear as well, last year. These vendors offer a generous timeframe on return, I think it's about 90 days which should allow you plenty of time to get, fit, and return the core.
I don't know how your German is, but you may want to check with the German Pagoda club as well as the usual UK and German vendors to see if there are any rebuilders on the continent that would save quite a bit on the shipping.
