while this has zero to do with NY state rules I'll just say this:
1. Cars that are 25 years old in Ct can acquire vintage plates, that costs about $100 to do. The advantage is cars registered thusly can only be appraised at a maximum of $500. It can be a worn out Toyota or a mint Ferrarri, $500 is the most they can base the property tax on. My Volvos went from $150 a year each to $11.

2. Once you have the vintage plates then the next step is to apply for permission to display "Year of Manufacture" plates. There is no charge for this servic, just arrive at a DMV inspection station with a pair (we need a pair of plates here) of plates, must be Connecticut plates in our case, that are representative of those that would have beeen issued to the car when new. I bought two pair at flea market, another at an estate sale.

The "vintage plates" must be kept in the car as the YOM plates will not be found in the data base, they are only mentioned on the YOM paper work that must also be carried in the car at all times.

3. No one at the DMV knew what I was talking about and had to go home and print out the statute and the forms from the state's web site and rub their noses in it.
Further I had to write my state representative to get an interpretation of the law from the state's legal department to prove that the plates could be worn all the time not just at shows as the folks at the DMV were insisting was the case.
The first cop that stopped me had no idea about the law either, so now I carry a copy of that in my cars too. I think the DMV, while having to comply with the law, doesn't like it.

Since I put mine on I've seen many more cars with them. I carried copies of the statute to car shows and handed them out to guys who had no idea the law existed.