A great way to provide an engine at a scale less than full and to provide the look without using the real Mc Coy if at full scale. Originals do exist but most are in the hands of replica builders and restoration shops. I have seen a half a dozen Gnome and Le Rhone engines on pallets in the storage shops at the Olde Kingsbury Aerodrome in Kingsbury Tx, where replica and restored WWI and classic era aircraft are built and restored.
Doc