My decision is certain

Hello and good morning together,
A few weeks ago, I asked for your opinion on whether to vote for or against a V8 4.2.
I would like to thank you for that. I've decided to do it.

Background to the consideration was that one of my best friends died in February. The estate includes a V8 and a 100 Avant 44Q. He wanted both structures.
Since I myself am a hobby screwdriver on various vehicles - I have already read in with you and prefer competent fellow humans - I am very grateful for any help I can get.

Here's my first question:

The V8 has the following chassis No. WAUZZZ4CZPN000612
and the 100 WAUZZZ44ZLN115018 .
There are different vehicles, however, I think that some identical parts are available.
Which parts can be used in both?

I am grateful for every answer.