Thanks for all the replies, it would seem that only the very early facelifts are truly compatible. I have had a lot of experience with the later model type injectors (not on Fiats) and can confirm that they need the individual injector correction codes programmed (CIIi) into the ECU (which must be the late type) to work correctly.
The latter plus the DPF precludes easy fitting, so I won't be doing that.
My dilemma is the looming strict emission testing with our oldest JTD 105, which has done a cool 500 000 ks and still runs like a watch. However, it smokes in the morning and the compression is low, indicating piston rings (minimum) possibly pistons rebores new valves and seats plus anything else under the hood - aaaargh!!
I have no idea if a replacement engine from a breaker would be any better, it's impossible to know until it's too late (ie fitted and running) and paid for, hence the hesitation.
The rest of the car is really solid, so scrapping is out of the question for the moment.
Cheers everyone!
Mik from Franceland