Now that I've had my say on Nv:
I think you are going to see Riverboats and Eastcoast Day boat collecting take over 2nd and 3rd place in the collecting world. Mainly because they are so accessable to a large part of the populace.
I advse collectors to record all information available on them. It will be history in the not too distant future. Especially the day boats, they are here today and gone tomorrow. History in the making. New collectors can collect more of them because they are cheaper right now.
Let me end this by saying, I don't care if my collection ever goes up in value. It makes for good conversation but it is not the reason I collect.