Your suggestions please, for tour ended things to do, which you did, including near tour hotel, and beyond things recomended in Rick's Berlin Guide book. We will be staying at tour hotel for four nights following the end of the tour in September, Thank you
Your interests would help to make a relevant suggestion.
If you are interested in seeing historic sites in Berlin, I mean traditional historic sites prior to 1933, go to eastern Berlin. Basically, historic Berlin is eastern Berlin. You could do your own Berlin itinerary regardless of what RS suggests based on your own priorities instead of strictly following the RS program. I don't use the RS book on Berlin at all.
historic Berlin is eastern Berlin
This statement gives imo a real wrong impression.
Historic origin Berlin was Nikolaiviertel only, located northern of river Spree island "Cölln" - more or less Museum Island today. Older than Berlin is Spandau, also some other neighborhoods of today's Berlin are older than Berlin.
When we speak about historical building prior 1933 (imo an irrelevant year) then the information is fully incomplete. 1920 was a relevant year with Greater Berlin Act. Hundreds to thousands of historic buildings in other parts of Berlin out of classic eastern center, e.g. Reichstag building, Charlottenburg Palace, Zitadelle Spandau, dozens of churches (e.g. the other two Basilica minor besids St. Hedwig, Ribbeck house, city bath of Charlottenburg, the old high embarkment of Berlin's subway from 1902, the Gothic house of Spandau, Gartenstadt Falkenberg, Alt-Köpenick 36, Köpenick Palace, restaurant Schupke ... just to name a few.
Nice tool for Berlin city map comparison between 1928 and 2015: https://1928.tagesspiegel.de/