i've had cali fortified wines from the 70s and 80s.
If you like port, you won't really like these. They offer none of the body/structure nor spices you'd look for in a proper port.
If you enjoy your Maury's / Banyuls and mixed it with something like a Duckwalk blueberry wine, then cali foritifed wines are nicely distinctive.
They're thinner than real ports but have a nice fresh brightness, noticeably sweet, touch of dustiness and some of them noticeable vanillan compounds from the oak that you wouldn't find in real ports.
I've hadnt had the wellingtons, but i've been double blinded plenty of times with port styled wines from cali with age on them and have never misguessed one as coming from portugal.