You can't expect to find the right parts at your general parts places. Depending on the parts, even the Mercedes Classic Center might not be able to help if they are specifically pre-war. Fortunately with a 170 V, some of the post-war parts will substitute, but not all. Niemoeller in Germany has the the largest stock, I think. There are others.
Do you have the original pre-war engine and transmission? This matters because the clutch would be different from a postwar. The throwout bearing should be available from Niemoeller, but it's possible that the pre-war version is different as well.
brake line, the rubber hoses? The easiest thing is to convert to post-war style fittings if you have the pre-war style hose. A photo would help here.
The rear cover for the transmission, a photo of it and the whole transmission would help, to determine which unit it is.
The king pin bushings are available from Niemoeller. Pre-war and post war are the same. I think they have king pins too. The bushings will need to be fitted.