This is my first motorcycle....same year same everything! It's a beautiful bike, congrats!
I see it's missing the bits that enclose the chain and rear sprocket.....I took mine off as well, they get old and loose so off it came. Once gone the chain without the support of the rubber boots will saw it's way thru the entry/exit ways at the back of the case. If you have the bits it's worth getting them back on, the chain and sprocket set will last forever.
A super tough old bike well worth the effort. You will be suprised how well it works on the street. Read in your manual (I have the exact same one) about the ISDT kit you can get for it.......the kit doubles hp numbers and turns the bike into an amimal.