The Fighting Observer was a small and unique group that trained beyond only observation.  Although the war ended as they were heading to France, they felt they wanted to distinguish themselves.  Thus creating the wing with flame.

The Bullion patch is rarer than the metal ones made.

Only one (maybe 2) other Bullion patches have been found.

This is unnamed

The wing is the prized piece on this uniform. 

The jacket was sent to Duncan Campbell for review and he too agreed it was authentic. 

This letter will be included.

He pulled some stitches out of wing to review back, construction and how long it was on uniform. 

This veteran most likely post occupation purchased a new uniform, carried over some of the insignia and then wore this for veteran events.

It would not be unusual for the uniform during occupation to be worn out on return. (Per Duncan)

You literally won't find another one like this.

This is the only Bullion to exist on a uniform that I am aware of.

If you could obtain the list of Fighting Observer pilots and locat one that lived in Ohio as this is where the uniform was tailored, that is a high probability that vet is whom this belongs to.

Based on my readings there were about 17 Fighting Observers. 

* this is a hard piece to let leave the collection but I must take care of priorities first.