I have used similar in several European phones. Do not know how eBay Germany works... just a hint.
http://tinyurl.com/3yw865s
dsk
Hi using ebay de is easy and you just log on the same they also translate stuff but sometimes not that well. They list some very nice phones have a look at the W48 models made in either black or white the prices are not too bad. They are very well made and spare parts are available. Hope this helps, they diagrams can be found on google just look up siemans w48 and an English site comes up. Post not too bad to UK but further afield could be a problem and cost.
The link in my first posting is dead, but I believe I did a ood buy when I got all this for NOK 565 delivered on my door. I guess I have transistorized capsuls for the rest of my life :)
I have problems with a good ID of the capsules, but they were used by the Norwegian telephone monoply in its days.
If tou could help me identify and even find data-sheets for them it would be fantastic.
For use in LB phones the voltage has to be riced because of the voltage drop in the diodes. wher I usually use 2 sells, I need 3. :-\
dsk