H6740 Mower Questions

I picked up a used 6740 disc mower yesterday. I'm new to disc mowers, but bar seems tight, spins good. I am missing the swath disc and the "top hat" on the end module. What purpose does it serve, do I need it? It has a couple issues with the canopy, and some cosmetic issues, but mechanically seems good. I'll be changing all the fluids and blades while I read up on what I need to know. Thanks.

H6740 Mower Questions