Proving this Ford Econoline was issued a fraudulent smog certificate may be difficult to prove as there is no way to make sure the smog technician who administered the smog check was aware of a blown head gasket problem or a fuel tank leak. You do have the option however to report the smog station which inspected this 1995 Ford Econoline to the Bureau of Automotive Repairs by calling (800) 952-5210. The BAR may step in and inspect the station in question, and may even request to inspect your Ford van.
In terms of recourse, you can always take the seller to small claims court to recover any damages. Often though winning a small claims battle involving a used vehicle is difficult. You may consult an attorney should you choose to take this step.