How to find the 4 digit engine code for a 2005 Ford Focus Mk2 1.4?

I asked a question a few weeks ago about my mechanic ripping me off for getting the tappets replaced.

Well I go back to them to find out that my engines already been taken apart by someone else beforehand and reassembled completely wrong. Therefore I would either need a new engine or take it back to ford to get it rearranged for £2k.

I would rather get a new engine installed for a cheaper price, but I have been reading up and It requires a 4 digit code, which I do not know.

Could somebody please tell me how I can get this code so I can find the right engine?

P.s if you're wondering why I'm not selling the car, it's because I'm going to get next to nothing for its value.

The 4 digit come is the name of the engine. Like mine is a b230 engine. In order to find out. Have a mechanic look on the engine block for the year and name of the engine. You can look up online where to find the code/name. It will be somewhere towards the bottom near the oil pan. That's where mine is.