The
Howard 500 was modified from the PV-1 Ventura, which was derived from the L-18, but was a substantially "hotter" aircraft. For one thing, the PV-1 (& PV-2) had P&W R-2800's, vs. R-1820s or R-1830s on the Lodestar. The wingspan remained 65 ft., but the chord was greater.
But except for cruising speed, you might have trouble telling them apart in the air.
