Welcome to the LC family
Realy a great looking vehicle. I like the rim covers. Please share more pics.
Similar issues with registration and taxes everywhere. Here in Germany you can register a vehicle basically only where you have a residence or business address registered. If the vehicle was registered in the EU, limits valid at the time of first registration are applied then also later.
Tax goes by age, type of fuel, emissions and displacement. Certain areas are off limit for older vehicles with higher emissions.
If it hadn't been registered in the EU yet, it's treated like a new car.

For older imported vehicles that basically means: No registration feasible. But also newer imported vehicles have issues as they need official certificates proofing emissions (including noise). Barely no manufacturer has those for vehicle configurations not intended for the EU.
For my 3.4 liter 1985 diesel, tax would be about 1300€ p.a. Only 4 figures, but still not affordable.
But there is one workaround: Historic vehicles recognized as a cultural heritage. Tax for those is only 192€ (!) and they are not subject to the areas off limit!
The vehicle needs to be at least 30 years of age, in original state and well maintained. The vehicle needs to pass a respective survey with an official expert. I was lucky to get that for my BJ73. The H at the end of my license plate indicates it.
No mercy for historic vehicles in CA?