I have an original 1948 plate registered to my Willys, it costs $32 to renew it every 10 years here, but it is limited use, but the plate was really nice.
I don't know all of the restrictions locally on the old plates but most people I've talked to said that nobody ever monitors their use. I believe those plates here never have to be renewed. Although I haven't gone through the process yet I was told it costs about $80 to register your car with them. I wish I'd have put a set on the Barracuda years ago. It would have saved me a lot of cash.
One thing that I was disappointed to find out was that I wouldn't be able to use my old plates from my 'Lil Red Express. I guess personalized plates don't qualify here.