You have to install the trezor back-end full node as well and have that connect to the Bitcoin Core full node ... so need to run two full nodes to support one wallet locally ...ok, nah.
I can see that you have edited your previous post, but this fragment clearly contradicts with it. You only need blockbook which apparently uses and maintains its own instance of Bitcoin Core. I asked on their Telegram channel if it was possible to connect an exiting Bitcoin Core instance to blockbook and I got "Yes" without any more details.
This config file might be worth taking a look at.