Maybe I'm not looking in the right places, but I just don't see a lot of the younger crowd wanting to expend that much time and energy to come up with the $$$$$ it takes to build a car these days....
In a way you are correct. Building versus re-modeling is the key. A lot of young kids (ages 16 - 24) would me more than willing to put $35,000 into a already built car like a Honda Civic or an Acura Integra then they would be to build a 32/33/34 from the ground up. First, they want instant gratification and not to have to wait for 6 months to a year for an all new car. And second many know that their investment will not only get them nearly instant wheels but very comfortable and very fast wheels. Many of those those hyper ricers (NOS) can blow the doors off most street rods, even rods with big, big blocks, especially from stop light to stop light. The money is not the problem for most of this age group (non-married, no dependents, no mortgage), the direction in which they intend to spend it is.

Who knows, one day when they are 50 years old or more, they may decide that street rods and customs really are pretty kool.