The TPA project has an article about this firm, which existed from 1844 to 1921. It had several changes of ownership and structure, including some around the time of the middle example card, which was posted in 1903. The logo given in the TPA article is S&S with the cockerell. That on the example cards is rather a monogram, S&S with an O round the & and the second S reversed, still with the cockerell. Two of these cards were evidently printed for sale in France.
The last example (actually the earliest card, looking forward to the new century) has as logo S u S B in a shield, ie S & S Berlin. It seems likely that this is also Schaefer & Scheibe though there may be evidence one way or the other that I haven't seen.
