The v55/5 was quite easy. There is a guide online if you google it.
The v627 was a bit harder.
As far as I can tell (and they didn't question my application) your car details go in the top right (not the donor) and the rest of the details are for the components.
With the receipts make sure that the chassis one says "new and unused on it". If it doesn't use word to add it in