As time goes on, there are more and more fans of Diesels out there. Often an area will be more receptive to them. You like them, build one for fun and see if can bring your money and time back.
Big however, if you look at how many hot rod buyers are present in the market, my guess is that 95% or more would not be your prospective buyer. That reduces the market down a bunch, likely futher than I am even guessing. So, while doing one or two and selling them may be possible, I would not hang my hat on making a living building them. Have the fun of doing one, and seeing how it goes.