I'm sure there are several of us that have the jack and arm available pretty cheap. Where are you located (USA, Canada, other)?
The plastic cover is probably best to buy new from your local dealer. A used one may not be worth dealing with after ~20 years of exposure to the underbelly and weather. I had one that looked pristine until I took it off and it cracked.
Search this part number if you want to buy online or compare prices: 98650411900
