a turbo works on the principal that it boosts the air flow. if the one off the 200tdi looks 100% the same then give it a go at the worst it will either under or over boost, you will know as soon as you test drive it, if it works let us all know
Both engines should displace very similarly the same volume of exhaust at the same rpm since both are 2.5 liter engines. Whether everything would match up I dunno, and as Yella indicates the boost may be set a little different.