^^^ Brett, I agree. My experiences have been the same. But, I've also had good luck with having vintage-style repro plates made (FOR DISPLAY PURPOSES ONLY) and getting them "DISPLAYED" on my car.
The key is to get the repros made from original type (heavy) steel plates...not aluminum...for your DISPLAY. Much more accurate.
The right era plates just look so good on a classic car. Just another detail touch for those of us who like such things.
Because I grew up in CA, my memory is full of esoterica like CA license number sequences, and the year that they would've been issued. I always want to be sure the ones I'm buying would've been in the range of plates distributed by the DMV for the year/month my car was originally sold.
For instance: The CA DMV doesn't seem to care if you put a ZZZ plate on a 1964 car, which would've originally had M, N or O as the first letter in its sequence, but I wouldn't do it. I can spot those mistakes from a mile away. Makes the "perfect" car look weirdly off.