This is a good original used steel Ducati MHR gas tank. I have had it sitting on my shelf for 30 years at least.... It was stripped down to bare metal and sprayed with some epoxy primer and the inside sprayed with emgine fogging oil then wrapped up in a plastic bag all this time. The inside is pretty clean with small and sporatic rusty spots. A soak with "Metal Rescue" will make it shiny inside again. The steel is damage free as I remember anyways. I would recommend media blast do the normal bodywork and repaint then you will be good to go.
It has the external threads for 16 x 1.0 fuel taps, silentbloc mounting up front and 2 button on the rear so it could be used on Super Sports or Hailwoods. It may fit 860 as well since mounting is similar but I have not checked on an 860 frame.
We have all the other stuff you may need to install this tank: