nice looking car, if it's had the denso then it's probably packed up and been too much to repair hence the swap, leave it as it is but if you do decide to swap it the loom in the back is slightly different so check first
red leather is highly sought after and you could see as much as £600 for that
i've got black alcantara in mine
it looks like it's already got the asbo brakes on it too and a nice exhaust

as for the option of fitting those seats into another ford, my mk3.5 focus has exactly the same plugs in the bottom of the seat as the mondeo, but it's probably wired up differently but i've only just had a look at the plug yesterday so it might not be but it's exactly the same plug to go in