I'd forget about it, let the lease run out.
First, I'd be afraid that anything I tried to use it for would become 'mission critical' once it existed, then I'm the one 6 months from now saying "Yeah... we can't get rid of that as we planned in the budget..."
Second, if you ever need something like that again, would you rather lease all new shiny stuff, or mess with rebuilding what you have as leftovers into something usable?
Its legacy stuff. get rid of it.
If you must, do something like run the Great Internet Mersenne Prime Search on it.