A person interested in collecting, studying and selling of old things

One word substitution is Antiquarian.

Antiquarian: a person who studies or collects antiques or antiquities.
Junk-dealer: a person who buys and sells discarded or secondhand objects.
Crank: turn (a handle) in order to start an engine.
Archealogist: a person who studies human history and prehistory through the excavation of sites and the analysis of artefacts and other physical remains.