My 89 LX

Hi, I have been watching these boards for a little over 6 months, and I finally have a question of my own. I would like to modify a Spoiler from a 1987 Merkur XR4Ti to fit on my own car. How can I make it fit [like how should I sand it and bondo it?] Is it worth it to do it? Also, will the MX-3 seats fit in the 89 Escort? and one last question, Can I use the center console from an EGT [1989] in my car? I want it in my car because I think it looks better. Will the computer [the car info thingy] still work in my car? Sorry if that was confusing for ya´ll, I´m not good at wording stuff.