Navman transom paddle wheel

I have a Navman MULTI 3100 on my boat, which records speed, distance and depth. The transducer is on the stern, the transom. The depth meter worked fine but the speed showed zero. Looking at the transducer I realised that the paddle wheel was missing. The spindle was there but no paddle wheel. A google search later I discovered that the company Navman (or North Star) was no longer trading and that all socks of the paddle wheel were gone (in the UK at least). Possibly it is this part: 46302