On this general subject - backing up a few decades:
GE was testing some airborne radar about 1960 and needed a "stealthy" target aircraft. They found & rehabbed a 1929-vintage Lockheed Vega - all wood except the engine & L/G. They even found a composite (micarta) prop for it. For that day's technology, it was fairly stealthy (I knew the guy who flew it).
How would it compare to today's stealth? Orders of magnitude?