Hello clock and watch enthusiasts! i have a clock by Heinrich Muller for KEINZLE. It is a lovely clock but I am not sure what to do with it. I am looking to sell it. Simply I just want to know how to look after it before I buy and check that it is still working. it seems to be running well but perhaps very slightly too slow. It has a plus/ minus at the back but over a few days after being on the + it is about 2 minutes slow. Is there anything I can do? i have cleaned up the brass as it was very dirty but I’m wary about doing it too vigorously and affecting the movement. I haven’t quite managed to clean the back fully as it requires a really good rub and am worried about going too far. Is it ok to clean the brass? One of the hands is very slightly bent downwards at the end. Is this normal? I am also not sure how to line up the world times (at the bottom) so that they are correct. Can I change this separately from the normal time? I have been told to hold off getting it serviced unless there is something majorly wrong. I wondered whether these problems are easily fixable? thanks for all your help- I realise that these queries are quite specific to the clock. I don’t know how to attach photos so I have included the selling page: *SALES LINK REMOVED* i know that such clocks can sell for more than 1000 pounds but realise that my clock requires a bit of work.