Hi Grzegorz,
It seems the main confusion (and please correct me if I am wrong), is that you are concluding that damaged or old parts from other aircraft were used in the built of late-war Me109's...such as the G-10. And using "Yellow 11" as an example.
It was proven many times already that this was never the case.
Which brought up the main topic of question...which was the reason for the second data plate on the G-10...and the G-10 only. This 2nd plate was on various new-built Me109G-10's, so I am trying to determine the exact use.
mike