Yep lose the bars.
Mine had grey grips originally, but they were in sad shape. I put the black ones on from another one I had.
I have 2 1954's, the one 1958 that you saw, and my brother has a really nice 57.
The styly you are looking at, you can put it in neutral, and pedal it over to start it without moving the wheel at all. I like tha, as it just seems cooler to start it sorta like a kick start. The 54's through '57 have a little bit different set-up inside, so they just lock the pedals in place when in Neutral.
You still might be able to find that cover at Motor West. Ya might have to call him and ask. His name is Matt. There are the two types like I was saying. The older version vents are a little smaller, and round. The one you are lookin at has a sorta bite mark out of it, where it is near the pedal shaft.