1980 xs special seat

[Wayne schultz]

So I have a 1980 xs400 special, had a universal seat on it when purchased, with sat directly on the battery. I got the seat part number from the local shop, the seat that is suppose to be on the bike, along with the grab bar is way larger than the bike it seems. Width along with the seat it so long and wide it sits right on the tail lights.
I am new to motorcycles, so I'm not sure where to go next.
Has anyone come across this before, did previous owners change parts that would cause this?

 

[CaptChrome]

Welcome to the forum.

I am suspecting that you have a bike that had some of its rear sub-frame chopped off. An '80 will look like the circled area below for the stock seat pan to fit: