Bearing dust cap part #?

Sucks losing it, recently I drove back roads going to a friends house and he noticed it was missing..So I drove back home slow to see if I can find it, no luck yet I'm going to hop on a bike to back track.. Darn thing never really fit decent to begin with it would always teeter back and fourth trying to install it.. It look like someone took frustrations out on it in its life time because I had to pound the lumps out of it... Think ill just use a sandwich bag and a rubber band...HeH