I have a ten year old Metz 60 CT-4 with a Sonnenschein A206/3.8K battery. I went to the Sonnenschein website and found that they have replaced this battery with a "more powerful" A506/4.2K battery. I also found in an old photography forum that states that this is just an expensive version of the A506/4.2S battery and that the "S" version can be used if the contacts are bent in the proper direction. Now, after all that, is my question -- has anyone had success with this method and if so, where can I purchase it? I have searched the web and can only find technical information on the batteries, not a retailer. Any help would be greatly appreciated.