Part nos of Harnesses needed for Analogue Tuner Part No.: A211 820 14 97

I know, it is the same reason why we do not get part numbers for all parts either. Car dealers get part numbers from an international database update by part makers, often a smal part like a wiring harness can have many part numbers for same part from different maker.
The only info I can get is for standard mercedes made parts, engine, body etc.
If you for example ask me part numbers for additional wiring etc. that info will be difficult to find.
All I can do is giving the part list for part you need, find sellers, and give help on fitting or troubleshooting.
As we are not car part sellers, you will need to contact one of the sellers listed on main solution, send them list , and they will return prices and some times part numbers for whole equipment needed.
If you ask explicitely for part numbers only, they probably will not give out parts numbers at all.