Well I was looking at some Boattail Speedsters and here is a few I found.
Here is a nice wooden one but I would still need to come up with the cowl for mine.
This would give a rumble seat for your friends. I'm not excited about the ribbed look.
This has an all wood body and looks like you could make it out of an old canoe.
This has to be the all time classic of Boattails. In the movie it was made from an old boat. If I could copy a car perfectly this would be my first choice.