FWIW, I have a garage full of old growth SYP that was the paneling inside my entire house. It was in literally every single room in here when we moved in.
I took it down because it had become kind of dark from the shellac yellowing from old age.
It's all 3/4" thick, random widths, and has some fancy molding carved in it.
Tongue & groove, but that can be cut off.