I figure just on the swap itself you'll be able to sell it for more than $800 so you're already ahead of the game just from that. Add in assorted other stuff and you could make some more money, but it wouldn't be all at once of course.
Also I'm a bit confused on this salvage deal. They give you a check for $800 less and you get the car back. But what's with the bid from the salvage yard? Do you have to give the car to the salvage yard once you strip off whatever parts are on it? Is there any limit to what parts you can take? I don't get it.