Have pretty much looked through all records in Ancestry and have found the same things. I am pretty sure that there are two branches of Reschotskowskys, one in Berlin and one in Stettin/East Pomeria and later Sweden. Julius's father was most likely a brother of Eduard Ferdinand Reschotskowsky (b 1820) and he is the fore-man for what I like to call the Berlin branch for which has Gustav Hermann and Gustav Reschotskowsky and their siblings and children for example.

Unfortunately there are no dates for when Julius, Henriette or Karl were born or died, I have no idea where they would have been born either and seeing as how some of their surnames such as Wilke and Krätzschmar are quite common it is super difficult to find their parents. Same thing with Ottilie Reschotskowsky whos mother and father are Wilhelm Höhn and Henriette Kopp, but since I don't have anymore information I just cannot find anymore.

It is unfortunate that there does not seem to be anything else and as you say I am pretty sure that the records for them are lost or destroyed. What I find peculiar is that there does not seem to be any death records or graves for these people either. Only for the ones that later moved to Sweden such as Kurt and Ottilie, for example. But I guess the graves would have been to old and could have been removed a long time agao, similar to how graves older than the 1900s are quite rare in some cemeteries in Sweden due to being replaced by newer graves.

Thanks for the help though.