Hello!

I´m sorry for any mistakes in technical english, it´s not my native language.
This is my problem:
The engine in my FL2 (2010 model), XS TD4, automatic gear, broke some weeks ago after a milage of 209.000 km. Engine number was DZ594067241224DT.
What I already learned, if I´m right, is:
DZ59=transmission code
4067241=serial number
224DT=engine type
Firstly a garage offered me an engine with number DZ594002108224DT. I did not agree because LR UK let me know that this was built in 2007, understandable according to the serial number part.
The same garage now offers me an engine with number DZ904002974224DT. The serial number seems like a 2007 engine as well. But here is this "DZ90" at the beginning. The garage tells me, this engine is from 2014 (Meanwhile, because of other circumstances, I do not trust them at least).

Does anybody know what are the meanings of "DZ59" and "DZ90"?
Did LR start new in counting the serial numbers (e.g. later when producing the "DZ90"?
Might there come some problems when assambling this "DZ90"?

I´m very thankful for any help in this matter!

Welcome Tom I personally can't help you but there are people on here who are knowledgeable in this kind of thing they will help i'm sure.