The thread called "Is MDHI going to make it?" drifted into a comparison of
the MD 500 and OH-58D aircraft. What follows is a discussion of the latter:

All the US Army OH-58Ds were rebuilt (OK, very, very extensively rebuilt and
modified) OH-58As. The rebuild process took the aircraft down to the
frames, replaced most of the sheet metal and a lot of the composites, built
new cowlings, fuel storage, rear compartments, tail booms, and all new
dynamic components, as well as completely replacing all the instrumentation,
avionics, and powerplants. But they started out as OH-58As. The only "new"
from the skids up OH-58D helicopters were built under contract to Taiwan.

Jim